Best Sourdough Blondies Ever! (Easy Discard Recipe)
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These Sourdough Blondies are everything you want in a simple, no-fuss dessert—chewy, buttery, and loaded with chocolate chips from edge to center. Just like my Sourdough Chocolate Chip Cookies, the batter comes together in just one bowl, so cleanup is quick and painless. They bake up beautifully, hold their texture when made ahead, and freeze well for an easy treat later on.
The sourdough discard adds just the slightest tang, which balances the sweetness and makes these blondies truly irresistible. Whether you’re baking for a crowd or just want something cozy to slice and enjoy throughout the week, this is one recipe you’ll come back to again and again.
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Why You’ll Love This Recipe:
Chewy and Soft Texture
These brown butter blondies stay soft in the middle with lightly crisp edges. The combination of sourdough discard, butter, and extra egg yolk keeps the batter tender. If you’re into chewy chocolatey cookies, you might also love these sourdough chocolate chip cookies.
Easy One-Bowl Recipe
Mix everything in one large bowl, then fold in the flour and chocolate chips. There’s no need for multiple dishes or complicated steps. If you enjoy quick mixes, this will probably become a go-to in your kitchen. These sourdough brownies are another recipe to try once you get the hang of this one.
Use Your favorite Add-Ins
I stuck with semi-sweet chocolate chips, but you can swap or add nuts. Pecans, walnuts, or white chocolate chips all work beautifully. This flexibility makes it easy to adapt for whatever flavor you’re craving.
Make Ahead or Freeze
These blondies slice and freeze well, so you can bake once and enjoy for weeks. Just wrap slices tightly or keep them in an airtight container. They also reheat gently for a warm, gooey treat anytime.
Ingredients & Substitutions
* To find precise measurements, scroll to the bottom of this post to find the recipe card*
- Flour – I used all-purpose flour for these sourdough blondies. If you are not using a kitchen scale, be sure to fluff and then scoop your flour into your measuring cup. If you want a perfectly chewy blondie, don’t add too much flour because it makes it turn out thick and kind of cakey.
- Baking Powder – Gives just enough lift to the blondies! Be sure to check the expiration date and replace your leaveners every 6 months, otherwise the cookies won’t rise properly.
- Sugars – I used a combination of light brown sugar and white sugar. Dark brown sugar could also work, offering the classic flavors of brown sugar, though I haven’t tested it in this recipe.
- Butter – For an extra nutty flavor, add browned butter instead of melted butter! Melt 226 grams (2 sticks) of unsalted butter and brown until left with 170 grams of browned butter. Allow the butter to cool for at least 30 minutes before adding to the wet ingredients. There’s no perfect gooey blondie without butter.
- Sourdough Discard – For blondie recipes and other sweeter recipes, I prefer to use fresh sourdough discard (room temperature), no older than 2 days. You can also use active sourdough starter. For the best results, be sure to use the same amount in grams.
- Mix-ins – I kept these blondies super simple and just added semi-sweet chocolate chips, but this is where you can let your creativity wild! From white, butterscotch or maple chips, to adding in some chopped pecans, walnuts, pistachios, or whatever you like.
- Salt – Helps balance the sweetness and brings out all the flavors in the batter. Any unrefined salt will work here, but I like using Redmond’s unrefined salt for those extra minerals.
- Egg – Adds structure and richness to the blondies.
- Egg Yolk – Egg yolks adds extra moisture and chew, which keeps the blondies soft in the center.
- Vanilla Extract – Adds warm vanilla flavor that plays really nicely with the brown sugar and sourdough.
How to Make Sourdough Blondies
- Preheat the oven to 350°F and grease an 8×8-inch baking dish, or line it with parchment paper. Set aside.
- In a medium bowl, whisk together the dry ingredients and set aside: flour, baking powder, and salt.
- In a large bowl, add the melted butter, sugars, sourdough discard, egg + egg yolk, and vanilla. Whisk until smooth.
- Using a rubber spatula, gradually fold the flour mixture into the wet ingredients. When there are just a few streaks of flour remaining, pour in the chocolate chips and fold until combined.
- Evenly spread the thick sourdough blondie batter into the prepared baking dish. Top with more chocolate chips, if desired.
- Bake for 35-40 minutes, or until the edges are just golden brown and the center is still soft. Be careful not to overbake.
- Cool completely before slicing and serving. Slice into 8-16 squares and enjoy!
How to Store:
Store blondies in an airtight container at room temp for up to 4 days.
For longer storage, wrap slices tightly in plastic or foil and freeze up to 3 months. To enjoy frozen slices, warm them gently. In the microwave, 15–20 seconds per slice** is plenty to get the center soft and melty. In the oven, set it to 300°F and heat 8–10 minutes until soft in the middle. Keep an eye on them so the edges don’t get too crisp.
FAQs
For these sourdough discard blondies, I recommend fresh discard no older than two days. Using older discard may change the flavor and texture slightly. An active starter works too, just match the weight called for in the recipe.
You could try it, but the brown butter flavor is a big part of the blondies’ richness. Results will vary and the texture may be less chewy. I haven’t tested it, so results may vary.
Yes. The whole egg gives structure, while the extra yolk adds moisture and chew, keeping the blondies soft in the center. Skipping the yolk could make the texture more cake-like.
Sourdough Blondies Recipe
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Equipment
Ingredients
- 245 grams all-purpose flour 1 3/4 cup
- 2 grams baking powder 1/2 teaspoon
- 3 grams fine sea salt 1/2 teaspoon
- 170 grams unsalted butter, melted 12 Tablespoon
- 210 grams light brown sugar, packed 1 cup
- 100 grams sugar 1/2 cup
- 100 grams sourdough discard 1/3 cup
- 1 large egg room temperature
- 1 egg yolk room temperature
- 8 grams pure vanilla extract 2 teaspoons
- 200 grams 1 cup chocolate chips, divided 1 cup
Instructions
- For an even more flavorful Sourdough Blondies, I highly recommend browning your butter before adding it to this recipe! It brings a delicious nutty flavor that goes perfectly with the chocolate chips. See Notes below on how to brown butter.
- Preheat the oven to 350 degrees F and grease an 8×8 baking dish or line with parchment paper. Set aside.
- In a medium bowl, whisk together the flour, baking powder and salt. Set aside.245 grams all-purpose flour, 2 grams baking powder, 3 grams fine sea salt
- In a large bowl, add the melted butter, sugars, sourdough discard, egg + egg yolk, and vanilla. Whisk until smooth.170 grams unsalted butter, melted, 210 grams light brown sugar, packed, 100 grams sugar, 100 grams sourdough discard, 1 large egg, 8 grams pure vanilla extract, 1 egg yolk
- Using a rubber spatula, gradually add and fold the flour mixture into the wet ingredients. When there are just a few streaks of flour remaining, pour in the chocolate chips, or other desired mix-ins, and fold until everything is combined.Feel free to include or substitute the chocolate chips for other options like chopped pecans or walnuts, or white chocolate, dark, maple chips, etc.200 grams 1 cup chocolate chips, divided
- Evenly spread the thick batter into the prepared baking dish. Top with more chocolate chips, if desired.
- Bake for 35-40 minutes or until the edges are just golden brown and the center is still soft. Be careful not to overbake.
- Cool completely before slicing and serving. Slice into 8 large or 16 small slices and enjoy!
Notes
How to Make Browned Butter
Melt 226 grams (1 cup) of unsalted butter in a medium-sized frying pan over medium heat, stirring occasionally. Once the butter is fully melted, it will begin to bubble. Continue to stir constantly until the bottom of the pan is covered with small amber specks (about 2–3 minutes). You should be left with 170g of browned butter. Carefully remove the browned butter from the heat and pour it into a large mixing bowl. Allow the butter to come to room temperature for at least 20-30 minutes.Ingredients & Substitutions
- Flour – I used all-purpose flour for these sourdough blondies. If you are not using a kitchen scale, be sure to fluff and then scoop your flour into your measuring cup. If you want a perfectly chewy blondie, don’t add too much flour because it makes it turn out thick and kind of cakey.
- Baking Powder – Gives just enough lift to the blondies! Be sure to check the expiration date and replace your leaveners every 6 months, otherwise the cookies won’t rise properly.
- Sugars – I used a combination of light brown sugar and white sugar. Dark brown sugar could also work, offering the classic flavors of brown sugar, though I haven’t tested it in this recipe.
- Butter – For an extra nutty flavor, add browned butter instead of melted butter! Melt 226 grams (2 sticks) of unsalted butter and brown until left with 170 grams of browned butter. Allow the butter to cool for at least 30 minutes before adding to the wet ingredients. There’s no perfect gooey blondie without butter.
- Sourdough Discard – For blondie recipes and other sweeter recipes, I prefer to use fresh sourdough discard (room temperature), no older than 2 days. You can also use active sourdough starter. For the best results, be sure to use the same amount in grams.
- Mix-ins – I kept these blondies super simple and just added semi-sweet chocolate chips, but this is where you can let your creativity wild! From white, butterscotch or maple chips, to adding in some chopped pecans, walnuts, pistachios, or whatever you like.
- Salt – Helps balance the sweetness and brings out all the flavors in the batter. Any unrefined salt will work here, but I like using Redmond’s unrefined salt for those extra minerals.
- Egg – Adds structure and richness to the blondies.
- Egg Yolk – Egg yolks adds extra moisture and chew, which keeps the blondies soft in the center.
- Vanilla Extract – Adds warm vanilla flavor that plays really nicely with the brown sugar and sourdough.
My family loved this quick & easy dessert! Thick, chewy and packed with chocolate chips – yum!