Sourdough Cosmic Chocolate Brownies (Printer-friendly)
Fudgy sourdough-infused chocolate brownies topped with mini chips and rainbow sprinkles for a playful, tangy twist.
# What You Need:
→ Wet Ingredients
01 - 1/2 cup unsalted butter, melted
02 - 7 oz dark chocolate (70% cacao), chopped
03 - 3/4 cup granulated sugar
04 - 1/4 cup plus 2 tbsp light brown sugar, packed
05 - 2 large eggs, room temperature
06 - 1 tsp pure vanilla extract
07 - 1/2 cup active sourdough starter (100% hydration, unfed or discard works)
→ Dry Ingredients
08 - 2/3 cup all-purpose flour
09 - 1/4 cup unsweetened cocoa powder
10 - 1/2 tsp fine sea salt
→ Cosmic Topping
11 - 3/4 cup mini chocolate chips or candy-coated chocolate pieces
12 - 3 tbsp rainbow sprinkles
# How to Make It:
01 - Preheat oven to 350°F. Line an 8×8-inch baking pan with parchment paper, leaving a 2-inch overhang on two sides for easy removal.
02 - Place the unsalted butter and chopped dark chocolate in a heatproof bowl. Set over a pot of barely simmering water (double boiler method) and stir gently until completely melted and smooth. Alternatively, melt in the microwave in 30-second intervals, stirring between each. Let the mixture cool for about 5 minutes.
03 - Add the granulated sugar and light brown sugar to the melted chocolate mixture. Whisk vigorously until the surface becomes glossy and well blended. Add the eggs one at a time, whisking thoroughly after each addition until fully incorporated. Stir in the vanilla extract.
04 - Gently fold the sourdough starter into the batter using a rubber spatula, blending until no streaks remain and the starter is evenly distributed throughout.
05 - Sift the all-purpose flour, unsweetened cocoa powder, and fine sea salt together directly into the batter. Fold gently with a spatula until just combined. Stop mixing as soon as no dry pockets are visible to avoid toughening the crumb.
06 - Pour the batter into the prepared baking pan and spread it into an even layer using the spatula. Scatter the mini chocolate chips or candy-coated pieces evenly across the surface, then finish with a generous layer of rainbow sprinkles.
07 - Place the pan on the center rack and bake for 28 to 32 minutes. Test for doneness by inserting a toothpick into the center—it should come out with a few moist crumbs clinging to it, not wet batter. For a denser, fudgier texture, lean toward the shorter bake time.
08 - Remove from the oven and allow the brownies to cool completely in the pan set on a wire rack. Once fully cooled, use the parchment overhang to lift the slab out and transfer to a cutting board. Slice into 16 even squares.
# Expert Tips:
01 -
- The sourdough starter adds a subtle tanginess that makes the chocolate taste deeper and more complex without anyone guessing your secret.
- That cosmic sprinkle topping turns an already incredible brownie into something that makes people grin before they even take a bite.
02 -
- Underbaking slightly is the single most important thing you can do for fudgy brownies, so pull them at 28 minutes if your oven runs hot.
- The sourdough tang is very subtle and will not taste sour, but if you are skeptical you can substitute 100 g of plain Greek yogurt for a different but equally delicious result.
03 -
- Weigh your flour rather than scooping it with the cup, because even a couple of extra grams turns a fudgy brownie into something disappointingly cakey.
- Let the melted chocolate cool until it is just warm to the touch before adding the eggs, and the batter will emulsify into a silky, glossy base that bakes with a beautiful crackled top.