Sourdough Toffee Chocolate Chip Cookies with Brown Butter

These Sourdough Toffee Chocolate Chip Cookies with Brown Butter strike the most irresistible blend of sweet and salty flavors! Thick and chewy with dense, gooey centers, they’re packed with melty semisweet and bittersweet chocolate, crunchy homemade brown sugar toffee, and rich caramel notes from browned butter. A sprinkle of flaky sea salt creates the perfect sweet-and-salty finish, while active sourdough starter or discard adds depth of flavor. The homemade toffee requires a few extra steps, but one bite will convince you it is completely worth it!

Essentials for the Perfect Sourdough Cookie

• Digital Kitchen Scale: Thick, chewy cookies depend on the right balance of flour, starter, and moisture. A digital kitchen scale removes the guesswork so your cookies spread properly while keeping those soft, gooey centers. I have used this exact scale in my kitchen for years, and it has never failed me!
• Stand Mixer: Properly mixing the butter and sugars creates the foundation for that dense, bakery-style texture. A quality stand mixer fitted with the paddle attachment makes quick work of this thick dough, but a handheld electric mixer works too. Just be careful not to overmix once the flour is added!
• Large Cookie Scoop: Nearly all of my sourdough cookie recipes are designed to make large, bakery-style cookies. A large cookie scoop portions the dough evenly so every cookie bakes at the same rate, giving you set edges and soft centers without some cookies becoming overdone while others remain underbaked.

Ingredients

Homemade Toffee Bits Ingredients

• ¼ cup salted butter (57g): For the most reliable results, use standard salted butter (regular American butter) containing approximately 80% butterfat. Higher-fat butter, including many European-style brands, contains less water and may make the toffee more likely to separate. If using a higher-fat butter (82% or more), add 1 tsp of water at the beginning of cooking to help compensate for the moisture differences in the butter. My recipe is tested with Kirkland Signature Salted Sweet Cream Butter from Costco.
• ½ cup light brown sugar, packed (110g): Pack it tight if measuring by volume!
• ¼ tsp salt: I prefer to use fine sea salt.

Sourdough Toffee Chocolate Chip Cookies Ingredients

• ½ cup salted butter (113g): We will be browning the butter to give it beautiful nutty caramel notes! After browning the butter, we will chill it back to “dent soft”, meaning it should indent with resistance when pressed, remaining cool to the touch and not shiny or oily. To use unsalted butter, add ¼ tsp additional salt.
• 1¼ cups light brown sugar, packed (275g): Pack it tight for the best chew and a perfect spread!
• 1 tbsp granulated sugar (13g): Helps create slightly crisp edges while maintaining the chewy center.
• ½ cup sourdough starter, active or discard, stirred down (150g): Active or discard starter works! Stir it down well before measuring by volume. For best accuracy, measure by weight.
• 2 large egg yolks (40g): Yolks only (skipping the egg whites) give the cookies a gooey, dense center that is never cakey.
• 2 tsp vanilla extract (10g): Pure vanilla extract provides the cleanest, best flavor.
• ¾ tsp salt (4.5g): Fine sea salt seasons the dough and balances the sweetness of the chocolate and toffee. If you’re not finishing with flaky sea salt, increase this to 1 tsp salt (6g).
• 1½ cups all-purpose flour, scooped (not spooned or sifted) (235g): I designed this volume measurement to be scooped directly out of the bag (not sifted or spooned and leveled). Pro Tip: For the best accuracy and overall cookie texture, measure flour by weight.
• 1 tsp baking soda (6g): Ensure you are using baking soda, not baking powder. They’re not interchangeable here.
• 6 ounces chopped baking chocolate, or 1 cup chocolate chips (170g / 6 oz): For this recipe, I love using a mix of 3 ounces semi-sweet chocolate chips and 3 ounces bittersweet chocolate baking bar, chopped. This creates the perfect blend of classic sweetness and rich chocolate flavor to complement the toffee.
• One full batch of the homemade toffee bits, about 1 cup or 150g: This small-batch toffee recipe makes just enough for one batch of cookies! To substitute store-bought toffee, use ⅞ cup (150g) of Heath Bits O’ Brickle English Toffee Bits.
• Flaky sea salt (to taste): A little flaky sea salt sprinkled over the cookies immediately after baking balances the rich chocolate and sweet homemade toffee. I highly recommend including it! If omitting the flaky salt, increase the fine sea salt in the dough to 1 tsp (instead of ¾ tsp) to help balance the sweetness of the chocolate and toffee.

How to Make Homemade Toffee Bits for Cookies

For the quickest workflow, brown the butter for the cookie dough first by following Step 1 below. Then, prepare the toffee while the browned butter chills. Alternatively, both the toffee and the brown butter can be prepared up to 1—2 weeks in advance for an even quicker bake day.

Prepare the Baking Sheet and Ingredients

Line a small baking sheet (although a regular-sized baking sheet is fine) with parchment paper. Measure the brown sugar and salt into a separate bowl and set aside. Have a whisk, spatula, and candy thermometer or instant-read thermometer ready. You can make the toffee without a thermometer, but the results may be less consistent.

Melt the Butter and Add the Sugar and Salt

In a small heavy-bottomed saucepan over medium-low heat, begin melting the butter. Once the butter is partially melted, add your brown sugar and salt, and whisk vigorously for about 1 minute (continuing over medium-low heat), until it has combined evenly.

Note: If you cannot get the ingredients to combine into one uniform mixture, remove the saucepan from the heat until the bubbling subsides, then add 1 tsp of hot water and whisk vigorously until it comes together smoothly. If the mixture repeatedly separates, reduce the heat slightly for the remainder of the cooking time.

Cook the Toffee to 300°F—305°F

Stir constantly but slowly as the mixture bubbles and boils. It will gradually thicken and become smooth, resembling melted peanut butter in both color and consistency. Do not leave the toffee unattended because it can burn quickly. Cook until the thermometer reaches 300°F—305°F, about 4–6 minutes. Immediately remove the saucepan from the heat and pour the toffee onto the prepared baking sheet. Use the spatula to spread it into a thin, even layer. Pro Tip: A thinner layer will be easier to crack into chunks once cooled!

If you do not have a thermometer, use the appearance and aroma of the toffee to help determine when it is ready. It should deepen to a richer amber color, develop a caramel aroma, and appear smooth and glossy like melted peanut butter. This generally takes about 4–6 minutes, although timing can vary.

Cool and Crack Into Pieces

Allow the toffee to cool and set for about 15–20 minutes. Use a heavy rolling pin or mallet to crack it into bite-sized chunks. I like a mixture of small, chocolate-chip-sized pieces and medium pieces about the size of a nickel. Set aside until you are ready to make the cookie dough. The toffee can also be prepared in advance.

How to Make Sourdough Toffee Chocolate Chip Cookies with Brown Butter

Step 1: Brown the Butter & Chill

Place butter in a small saucepan over medium-low heat. Cook for about 5–7 minutes, stirring constantly. It will foam up, then the foam will dissipate and it will quickly turn golden, develop brown flecks, and take on a nutty caramel aroma.

Remove the browned butter from heat, transfer to a shallow bowl, and place in the fridge until it firms back into a “dent soft” consistency (about 1 hour in the fridge). “Dent soft” means it is opaque and solid but still pliable. When pressed with a finger, it should indent with some resistance and feel cool to the touch, not oily or greasy.

Step 2: Make the Toffee

While the brown butter chills, prepare one batch of the homemade toffee bits according to the directions above. Allow the toffee to cool completely, then crack it into pieces. You can prepare the toffee in the same saucepan you used to brown the butter.

Step 3: Preheat Oven & Prep

Once the butter has been browned and cooled, and the toffee is prepared and cracked into pieces, it’s time to make the cookie dough. Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.

Step 4: Cream the Butter & Sugars

Beat the brown sugar, granulated sugar, and cooled brown butter until well combined with no remaining butter chunks., about 3 minutes. This works best with a stand mixer (paddle attachment) or a handheld electric mixer. The resulting look and texture will resemble wet beach sand.

Step 5: Add the Wet Ingredients

Add the sourdough starter, egg yolks, vanilla extract, and salt. Beat until smooth and slightly frothy. Pro Tip: Scrape down the sides of the bowl to ensure the starter is fully incorporated with no streaks remaining.

Step 6: Incorporate the Dry Ingredients

Add the flour and sprinkle the baking soda evenly over the top. Turn the mixer to low speed and stir until just combined. Critical Step: Stop mixing when you still see a few tiny streaks of flour remaining. Overmixing here develops too much gluten, making cookies tough rather than gooey and chewy.

Step 7: Fold in the Toffee and Chocolate

Gently fold in the prepared toffee chunks (reserve 2 tbsp of toffee for topping, if desired) and the chocolate chips or chopped chocolate using a spatula, or mix on the lowest speed for just a few rotations. Stir only until evenly distributed to avoid overworking the dough.

Step 8: Scoop & Top

Portion the dough into large scoops using a cookie scoop or spoon (3 tbsp / 70g each). Place 6 scoops per baking sheet to allow space for spreading. Pro Tip: For a bakery-style look, press extra chocolate chips or chunks onto the top of each dough ball before baking to ensure they remain visible. Wait until immediately after baking to add the reserved toffee so the pieces remain intact.

Step 9: Bake & Top

Bake for 12–15 minutes, rotating the pan halfway through. Remove when the edges are set and slightly golden but the centers still look soft. Immediately sprinkle with flaky sea salt and top with the reserved toffee, if using. If any of the cookies have uneven edges from melted toffee, just scoot those in with a spatula before the cookies cool. Pro Tip: Immediately after removing the pan from the oven, firmly tap it against a heatproof surface a few times to deflate the cookies. This creates a denser, gooier texture. Bake in batches. Recipe makes about 16 cookies.

Step 10: Cool on Baking Sheet

Allow the cookies to set on the hot baking sheet for 7 minutes before transferring to a wire rack. Moving them too early may cause them to fall apart.

Storage Tips

Store completely cooled cookies in an airtight container for up to 5 days at room temperature.

Why This Recipe Works

These sourdough toffee chocolate chip cookies layer rich, caramelized flavor into every bite! Browning the butter adds deep, nutty notes that perfectly complement the homemade brown sugar toffee, while bittersweet chocolate balances the sweetness and keeps the cookies from tasting overly rich. A sprinkle of flaky sea salt brings all those flavors together and creates an irresistible sweet-and-salty flavor.

The dough is carefully balanced to produce thick, chewy cookies with crisp edges and dense, gooey centers. The combination of melty chocolate and crunchy toffee bits is a DREAM! Using egg yolks instead of whole eggs limits excess moisture, while active sourdough starter or discard adds depth of flavor without making the cookies taste sour. Best of all, there is no need to chill the finished dough. Once the brown butter has cooled and the homemade toffee is ready, you can scoop and bake! Both components can also be prepared in advance for an even quicker bake day.

The Sourdough Cookie Lady Tips

• Make the homemade toffee. I know there are substitutions provided if you’re in a pinch, but I just have to say that making your own homemade toffee for these cookies is a game changer and absolutely worth the extra steps!
• Don’t skip the flaky salt. The caramel notes from the browned butter and crunchy toffee pair perfectly with the semisweet and bittersweet chocolate, while the flaky salt adds a delicate crunch and creates the perfect sweet-and-salty balance. This combination makes these cookies completely irresistible!
• Let the brown butter become “dent soft.” To keep this a no-chill dough, the cooled brown butter should indent when pressed but still feel cool and offer some resistance. It should not look melted, shiny, or oily.
• Do not overbake the cookies. Remove them when the edges are set but the centers still look soft and slightly underbaked. They will continue to firm up on the hot baking sheet, giving you that dense, gooey center instead of a dry or cakey texture.
• Use only the egg yolks. Whole eggs add too much moisture and can push the cookies toward a cakey texture. Egg yolks help keep the centers dense, soft, and chewy.
• Measure the flour and sourdough starter by weight if possible. The balance between the flour and moisture from the sourdough starter makes a big difference in the final texture. Weighing them helps prevent cookies that spread too much or turn out overly thick and dry.
• Tap the pan after baking. Tapping the pan right after baking helps deflate the centers slightly for a denser, gooier bite.

Frequently Asked Questions

What do I do if my toffee didn’t set hard enough to crack?

If the toffee remains soft after cooling completely, it was likely undercooked and did not reach the hard-crack stage. For the most reliable results, prepare a new batch and cook it to 300°F–305°F before immediately removing it from the heat and spreading it on the prepared baking sheet according to the directions. Using a batch that is too soft will create more of a caramel flavor than a toffee flavor, and will not have the classic crunch of a true toffee.

Do I have to chill the dough before baking?

No, you don’t! This is a no-chill dough, so you can bake the cookies immediately for a no-wait sourdough treat. Keep in mind, however, that the browned butter must chill back to a “dent soft” consistency before you mix the dough. Both the brown butter and homemade toffee can be prepared in advance.

Will these cookies taste sour?

The sourdough discard acts as a flavor enhancer, adding a subtle depth that balances the sweetness of the other ingredients. To ensure the cookies do not taste sour, use starter or discard that has been fed within the last two weeks. Older discard and the long-fermented option (1–3 days in the fridge) may create a more noticeable sourdough tang!

Can I use active starter instead of discard?

Absolutely! Both active starter and sourdough discard work well here. Because the dough is mixed and baked immediately, the starter does not need to be active for leavening. Active starter will generally provide a slightly milder flavor.

Why did my cookies come out cakey instead of chewy?

Cakey cookies are commonly caused by adding too much flour or using whole eggs instead of egg yolks. For that signature dense, chewy texture, weigh the flour in grams, use only the yolks, and remove the cookies from the oven when the edges are set but the centers still look soft. Overbaking can make the cookies dry, while overmixing after adding the flour can create a tough, bread-like crumb. Mix on low speed only until a few tiny streaks of flour remain, then gently finish incorporating them with a spatula.

Can I freeze sourdough cookie dough?

Absolutely! For best results, follow this flash-freezing method:

1. Scoop: Portion the sourdough toffee chocolate chip cookie dough into balls (3 tbsp / 70g each) and place them on a parchment-lined baking sheet. They can be close together, but make sure they are not touching.
2. Flash Freeze: Place the sheet in the freezer for about 1 hour, or until the dough balls are firm to the touch. Pro Tip: Before freezing, optionally press a few extra chocolate chips or chunks onto the dough balls so they remain visible after baking. Wait until immediately after baking to add the flaky sea salt and extra toffee bits.
3. Store: Transfer the frozen dough balls into a gallon freezer bag. They can be stored in the freezer for up to 3 months!

Pro Tip: Double the recipe and intentionally freeze an extra batch! This gives you ready-to-bake brown butter toffee chocolate chip sourdough cookies whenever your sweet tooth hits.

Tips For Baking Frozen Dough:

Thaw Partially: For best results, allow frozen dough to sit at room temperature for 30–60 minutes before baking. This helps achieve a texture and baking time nearly identical to a fresh batch of dough.

Potentially Increase Bake Time: You may need to add 1–2 minutes to the baking time if the dough is still colder than fresh dough would be.

How to Make Long-Fermented Sourdough Toffee Chocolate Chip Cookies

Note that the toffee may absorb moisture and soften during a long-fermentation. To long-ferment the dough for deeper flavor and a slower fermentation option that some bakers prefer for digestibility, follow these simple directions:

1. Prepare: Follow the recipe directions to make the dough.
2. Cold Ferment: Cover the bowl with plastic wrap, or transfer to an airtight container. Refrigerate for 1–3 days. Note: The longer the dough ferments, the more noticeable the sourdough tang may become.
3. Bring to Room Temp: Dough temperature significantly affects how much the cookies spread. Remove the dough from the refrigerator about 1 hour before baking, or allow it to rest until it is soft enough to scoop easily.
4. Scoop & Bake: Once the dough is soft enough to scoop, portion it into scoops (3 tbsp / 70g each) and bake according to the recipe directions, then top with flaky sea salt!

Troubleshooting: If the cookies remain unusually thick or do not spread enough, the dough was probably still too cold when it went into the oven.

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