Yields: 16 generous brownies
Prep Time: 20 minutes
Bake Time: 30-35 minutes
Cooling Time: 1-2 hours (highly recommended!)
Total Time: 1 hour 50 minutes (plus cooling)
Recipe Intensity: Easy to Medium – This is a straightforward, one-bowl recipe, but it requires attention to mixing technique to achieve that perfect crackly top. No special skills are required, just a willingness to follow the steps.
Ingredients
For the Brownie Batter:
-
½ cup (115g) unsalted butter
-
1 ½ cups (300g) granulated sugar
-
⅔ cup (65g) unsweetened cocoa powder, natural or Dutch-processed
-
½ teaspoon fine sea salt
-
1 cup (240g) active or discard sourdough starter (100% hydration)
-
2 large eggs, at room temperature
-
1 teaspoon vanilla extract
-
½ cup (65g) all-purpose flour
-
½ cup (85g) semi-sweet or dark chocolate chips
For the Optional Swirl:
-
⅓ cup (85g) smooth peanut butter, Nutella, or cream cheese, softened
Instructions
Step 1: Melt and Mix the Foundation
Preheat your oven to 350°F (175°C). Line an 8×8 inch baking pan with parchment paper, leaving an overhang on two sides for easy removal. This is crucial for getting clean, perfect brownie squares.
In a large, microwave-safe bowl, combine the butter, sugar, cocoa powder, and salt. Heat in the microwave in 30-second bursts, stirring well after each interval, until the butter is fully melted and the mixture is smooth and hot to the touch. Alternatively, you can do this in a saucepan over medium heat.
Why this matters: Melting the butter with the sugar and cocoa dissolves the sugar and “blooms” the cocoa, creating a rich, fudgy base and helping to form that signature shiny, crackly crust.
Step 2: The Cooling Pause
Allow the hot chocolate-butter mixture to cool for 5-10 minutes. This is a critical step! If the mixture is too hot, it will cook the eggs when you add them, resulting in a cakier, less fudgy brownie.
Step 3: Incorporate the Sourdough and Eggs
Once the mixture is warm but not hot, whisk in the sourdough starter until fully combined. The batter will be thick and glossy.
Next, add the room-temperature eggs, one at a time, whisking vigorously after each addition. Finally, whisk in the vanilla extract. Continue to whisk for a full 60 seconds. This step is non-negotiable for that crackly top; it aerates the mixture and helps dissolve the sugar further.
Step 4: The Final Fold
Switch from a whisk to a spatula. Add the all-purpose flour to the batter and gently fold it in until just a few flour streaks remain. Before they fully disappear, add the chocolate chips and fold until everything is just combined. Do not overmix! Overmixing will develop gluten and make your brownies cakey instead of fudgy.
Step 5: Pan, Swirl, and Bake
Pour the thick, luxurious batter into your prepared pan and spread it evenly into the corners.
For the optional swirl: Drop small dollops of your chosen swirl ingredient (peanut butter, Nutella, etc.) over the surface of the batter. Use a knife or a toothpick to gently swirl it into the top layer of the brownie batter, creating a beautiful marbled effect.
Bake for 30-35 minutes. The brownies are done when the top is shiny and crackly, and a toothpick inserted into the center comes out with a few moist crumbs attached, but not wet batter. It is better to under-bake slightly than to over-bake!
Step 6: The Ultimate Test of Patience
Remove the brownies from the oven and place the pan on a wire rack. This is the hardest part: you must let them cool completely in the pan, for at least 1-2 hours. The brownies continue to set as they cool, and cutting into them warm will result in a gooey, messy (albeit delicious) situation. For the cleanest, most perfect squares, you can even refrigerate them for an hour after they’ve cooled to room temperature.
Once completely cool, use the parchment paper overhang to lift the entire brownie slab out of the pan. Place it on a cutting board and slice into 16 squares with a sharp knife.
Nutrition Information
Please note: The following is an estimate based on the ingredients used and can vary significantly based on specific brands and additions like peanut butter swirl. It is provided for informational purposes only.
Serving Size: 1 brownie (1/16 of the recipe)
Calories: ~220
Total Fat: 10g
-
Saturated Fat: 6g
-
Trans Fat: 0g
Cholesterol: 40mg
Sodium: 95mg
Total Carbohydrates: 32g -
Dietary Fiber: 2g
-
Sugars: 24g
Protein: 3g
Dietary Considerations: This is a decadent treat. For a gluten-free version, use a 1:1 gluten-free flour blend and ensure your sourdough starter is gluten-free. To make them dairy-free, use a plant-based butter alternative. The sugar content can be slightly reduced, but it may affect the texture and crackly top.
Storing, Freezing, and Pro-Tips
-
Storing: Store cooled brownies in an airtight container at room temperature for up to 3 days or in the refrigerator for up to a week. The flavor often deepens and becomes even more complex on the second day!
-
Freezing: These brownies freeze exceptionally well. Wrap individual squares in plastic wrap and place them in a freezer bag for up to 3 months. Thaw at room temperature or warm gently in the microwave.
-
Active Starter vs. Discard: You can use either! An active starter may impart a very slight, more complex tang, while a ripe discard is perfect for a rich, fudgy result. Do not use starter that has been stored in the fridge for weeks and has a layer of hooch; this can create an off-flavor.
-
The Room Temperature Egg Rule: Using room-temperature eggs is crucial. Cold eggs can cause the melted butter to seize, making the batter greasy and difficult to emulsify properly.
-
Don’t Skip the Whisking: The vigorous whisking after adding the eggs is the primary leavening agent for these brownies, creating air pockets that rise to the top and form that beautiful, shiny crust.
The Sourdough Brownie is more than a recipe; it’s a revelation. It transforms a simple discard into the star ingredient of a decadent, sophisticated dessert that will have everyone asking for your secret. It’s the perfect bridge between the artisanal world of sourdough and the universal love of chocolate, creating a treat that is truly greater than the sum of its parts.