Sourdough discard brownies peanut (Printable Version)

Moist, fudgy chocolate brownies enhanced with sourdough discard and a peanut butter swirl.

# Needed Ingredients:

→ Chocolate & Butter

01 - 1/2 cup unsalted butter
02 - 1 cup semisweet chocolate chips or chopped chocolate

→ Wet Ingredients

03 - 1/2 cup sourdough discard, unfed
04 - 1 cup granulated sugar
05 - 2 large eggs
06 - 1 teaspoon vanilla extract

→ Dry Ingredients

07 - 1/2 cup all-purpose flour
08 - 1/4 cup unsweetened cocoa powder
09 - 1/2 teaspoon fine sea salt

→ Peanut Butter Swirl

10 - 1/3 cup creamy peanut butter
11 - 1 tablespoon powdered sugar, optional

# Steps:

01 - Preheat oven to 350°F. Line an 8x8 inch square baking pan with parchment paper.
02 - In a microwave-safe bowl, melt butter and chocolate together in 30-second intervals, stirring until smooth. Allow to cool for 3 minutes.
03 - In a large mixing bowl, whisk together sourdough discard, granulated sugar, eggs, and vanilla extract until well incorporated.
04 - Pour the cooled chocolate mixture into the wet ingredients and whisk until smooth.
05 - Sift flour, cocoa powder, and salt directly into the bowl. Fold gently with a spatula until just combined, being careful not to overmix.
06 - Pour batter into the prepared pan and smooth the surface evenly.
07 - In a small bowl, combine peanut butter and powdered sugar if using. Drop spoonfuls of peanut butter mixture over the brownie batter. Use a skewer or knife to gently swirl the peanut butter throughout the batter.
08 - Bake for 28 to 32 minutes, or until the center is just set and a toothpick inserted in the center comes out with moist crumbs.
09 - Cool completely in the pan before cutting into 16 squares.

# Expert Advice:

01 -
  • Finally, a legitimate reason to keep sourdough discard instead of dumping it down the sink.
  • These brownies stay fudgy for days without that weird box-mix staleness.
  • The peanut butter swirl looks impressive but requires zero special skills or decorating tools.
  • One bowl of batter, one pan, minimal cleanup—perfect for a weeknight craving.
02 -
  • Sourdough discard varies wildly in hydration depending on how you feed your starter—if your batter looks too wet, don't panic, just whisk in an extra tablespoon of cocoa powder and reduce baking time by a minute or two.
  • Opening the oven door before 25 minutes causes temperature drops that can result in underbaked centers, so set a timer and trust the process.
  • These brownies actually improve after a day or two as flavors meld and moisture redistributes, so making them ahead of a gathering is a genuine advantage, not a shortcut.
03 -
  • Keep your sourdough discard at room temperature unfed in the fridge—it's actually more stable and flavorful than freshly fed starter, and it performs better in baking.
  • Invest in a kitchen scale, because the difference between level-scooped flour and weighed flour can be the difference between fudgy success and dense disappointment.
Go Back