Sourdough Brownies Peanut Swirl (Print Version)

Fudgy chocolate brownies with sourdough discard and a creamy peanut butter swirl for a moist, rich treat.

# What You'll Need:

→ 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

→ Swirl

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

# How to Make It:

01 - Preheat oven to 350°F. Line an 8x8 inch square baking pan with parchment paper.
02 - In a microwave-safe bowl, combine butter and chocolate chips. Microwave in 30-second intervals, stirring between each burst, until completely melted and smooth. Allow mixture to cool for 3 minutes.
03 - In a large mixing bowl, whisk together sourdough discard, sugar, eggs, and vanilla extract until well incorporated.
04 - Pour the cooled chocolate mixture into the wet ingredients and whisk until the batter achieves a smooth consistency.
05 - Sift flour, cocoa powder, and salt over the chocolate mixture. Using a spatula, fold gently until just combined, being careful not to overmix.
06 - Pour batter into the prepared baking pan and smooth the surface with a spatula.
07 - In a small bowl, combine peanut butter with powdered sugar if desired, mixing until smooth. Drop spoonfuls of peanut butter mixture over brownie batter. Using a skewer or knife, create a swirled pattern by gently dragging through the mixture.
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 - Allow brownies to cool completely in the pan before slicing into 16 squares.

# Additional Tips::

01 -
  • Your sourdough discard finally has a purpose beyond guilt, making these brownies stay moist for days.
  • The fudgy center requires no special techniques—just straightforward mixing and a little patience with the oven timing.
  • That peanut butter swirl isn't just decoration; it adds a salty-sweet depth that elevates chocolate from basic to craveable.
02 -
  • Overbaking by just two minutes turns fudgy brownies into dry ones, so set a timer and check early; the center should still feel slightly underbaked when you pull the pan out.
  • Sourdough discard varies in thickness depending on how much liquid has separated, so if yours is very liquid, you might need to reduce it slightly to avoid a sunken center.
  • The peanut butter swirl sinks and blends during baking rather than staying as visible stripes, so don't worry if it disappears—it's still there adding moisture and flavor.
03 -
  • Measure your flour by weight whenever possible—those kitchen scales cost less than a bad batch of brownies and prevent the dense, dry disasters that come from compacting flour into your measuring cup.
  • Don't fear the moist crumb test; brownies continue to cook slightly as they cool, so pulling them out when they still jiggle in the center guarantees fudgy results even after they've completely cooled.
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