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These Sourdough Blondies have the perfect blondie consistency and tons of flavor from sourdough discard and brown butter. Best of all, they are really quick to make. With this versatile recipe, you can get creative with your mix-ins, from chocolate chips, to butterscotch chips, caramel chips, nuts, M&Ms, Cadbury mini eggs (hello, Easter!), or maybe go with dried fruit like cranberries or raisins!
Ingredients to Make Sourdough Blondies
Based on my Sourdough Discard Chocolate Chip Cookie recipe, It takes just a handful of ingredients to make these delicious Sourdough Blondies:
- Butter. Use it cold, frozen or at room temperature. No need to plan ahead! We are going to melt it and then cook it until it is browned.
- Brown Sugar. You can use light or dark brown sugar, or a combination of both.
- White Sugar. Adds sweetness to complement the molasses tones in the brown sugar.
- Eggs. In my cookie recipe, I use two large egg yolks. Here, we use two whole large eggs which helps us get the correct blondie consistency.
- Vanilla. Adds wonderful flavor to the blondies.
- Sourdough Discard. Let it sit out at room temperature while you brown the butter and allow it to cool.
- Flour. Regular all purpose flour is perfect here.
- Baking Powder. This was another change from my cookie recipe which uses baking soda. To obtain an even bar that rises just a little without collapsing in the middle, we reduce the amount of the chemical rising agent. Baking powder works more evenly in this recipe.
- Salt. As in most recipes, salt balances the flavor. For an extra perk, I top these blondies with flaky sea salt.
- Chocolate Chips. My favorite combination is equal amounts of bittersweet chocolate chips and semisweet chocolate chips with a handful of milk chocolate chips. But this is where you do you! Use any combination of chips (caramel, butterscotch, cinnamon, white chocolate), nuts, and/or dried fruit (cranberries, raisins). My go-to for bittersweet and semisweet chocolate chips is Guittard. For milk chocolate, I am exceptionally loyal to Callebaut.
How to Make Sourdough Blondies
Brown the Butter
This is the only “difficult” step in making these Sourdough Blondies. (There is really no difficulty. Just cook on a low flame the first time to get the feel for when it is done.) It is also the most important step. Brown butter adds wonderful flavor to any dish. That is especially true here. If you have never browned butter, check out my post Brown Butter: What is it and How to Make it.
Learning to brown butter may take some practice. Just keep in mind that the butter can go from brown to burnt very quickly. I find that, cooking on a medium-low flame, once the butter gets foamy to the point where you cannot see through the foam when you push it aside with a heatproof spatula, removing it from the heat and stirring until the foam dissipates so you can see the browned milk solids seems to be a good way of doing it. My favorite heatproof spatulas are from Gir which you can find on Amazon.
Mix in the Sugars
Immediately after browning the butter, stir in both sugars. Melting the sugars in the hot browned butter helps achieve a shiny top on the baked blondies. Pour the butter/sugar mixture into a heatproof mixing bowl and allow it to cool to room temperature. This usually takes 15-30 minutes.
Mix in the Liquid Ingredients
Once the mixture is cooled, mix in the eggs and the vanilla until fully combined. Then mix in the sourdough discard, also just until it is fully combined and no streaks show.
Fold in the Dry Ingredients
Fold that in the dry ingredients just until the flour is no longer visible. Then mix in the chocolate chips or whatever additions you are using.
Bake
I find a 9-inch by 9-inch square pan is ideal for this recipe, as it gives the perfect height. My pan of choice is USA Pans. If you like a somewhat thinner blondie, you can certainly bake in a 9-inch by 12-inch pan, but you may have to reduce the baking time by a few minutes. Bake in a moderate oven, at 350°F, for 35-40 minutes. (My sweet spot in my oven is 37 minutes.) A toothpick inserted in the middle should come out clean, and the edges should be lightly browned and just started to pull from the sides of the pan. Allow to cool completely before cutting.
Sourdough Blondies
Ingredients
- 227 grams unsalted butter (16 Tablespoons or 2 sticks)
- 113 grams sourdough discard (at room temperature (½ cup))
- 280 grams all purpose flour (2⅓ cups)
- ½ teaspoon baking powder
- ¾ teaspoon salt
- 146 grams brown sugar (⅔ cup, firmly packed, light or dark)
- 133 grams granulated sugar (⅔ cup)
- 2 teaspoons vanilla
- 2 large eggs
- 300 grams chocolate chips (1¾ cups, see note below)
- Flaky sea salt
Instructions
- Preheat the oven to 350°F.
- Lightly grease a 9-inch square pan and line it with parchment paper.
- In a large saucepan, melt the butter over low heat. Once fully melted, increase the heat to medium-low to cook the butter, stirring frequently with a heat proof rubber spatula, being sure to scrape the sides of the pan frequently. The butter will start popping and crackling and then start foaming. The part of the butter that will start browning is the milk solids which will be on the bottom of the pan. This is why you need to keep stirring and scraping the sides of the pan so that the milk solids brown evenly. Once the butter is foaming to the point where you cannot see the bottom of the pan, remove the pan from the heat, stirring the mixture, until you can see the bottom. If the bottom is showing lots of brown specs, it is done. Immediately mix in the brown sugar and white sugar. Transfer to a heat proof bowl to cool to room temperature, approximately 15-30 minutes, stirring occasionally.
- In a small bowl, whisk together the flour, baking powder and salt.
- Once the brown butter/sugar mixture is cooled, mix in the eggs and the vanilla until fully combined.
- Stir in the sourdough discard until fully combined.
- Add the dry ingredients and mix just until they disappear. Mix in the chocolate chips.
- Spread into prepared pan. Sprinkle with flaky sea salt.
- Bake for 35-40 minutes.
- Place on wire rack and cool completely before cutting.
7 Comments
I just made this recipe. It was incredibly easy and they came out perfect. My family devoured them! Perfect texture and fantastic use of my sourdough discard!
The best thing I’ve ever made with Discard. SO good they didn’t even make it into work with me opps!
The sourdough discard gave these a subtle depth that balanced the sweetness of the chocolate and brown sugar nicely.
These were delicious! And surprisingly simple to make. I will definitely be making again!
My only disagreement here is waiting until they are fully cooled to slice! 😂
That is a BIG ask!
Hands down best blondies ever. I’ve actually done it both ways- in the 9×9 square and in the 9×13 rectangle. Both excellent. Rectangle – thinner (obviously!). Square pan little thicker. So so good.
Favorite part- not having to put brown butter in the fridge and then soften again. Like I can not have brown butter on hand and decide to make these and still make them right then!!!
Excellent recipe- thank you! Great combo on chocolate too! I like to add a sprinkling of Trader Joe’s salted caramel chips as well in place of some of the milk or semisweet.
I loved this but substituted the chocolate chips for butterscotch and it was delightful!
These sourdough blondies are so tasty and super easy to make. Will be making them again!