Sourdough Cosmic Chocolate Brownies (Printable Version)
Fudgy chocolate squares with sourdough tang and a glittering candy-topped finish, rich and indulgent.
# 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 packed light brown sugar
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
# Directions:
01 - Preheat oven to 350°F. Line an 8×8-inch baking pan with parchment paper, leaving an overhang on two sides for easy removal.
02 - Combine the butter and chopped dark chocolate in a heatproof bowl set over simmering water, stirring gently until fully melted and smooth. Alternatively, microwave in 30-second intervals, stirring between each. Let the mixture cool for about 5 minutes.
03 - Whisk the granulated sugar and brown sugar into the melted chocolate until the mixture becomes glossy. Add the eggs one at a time, whisking thoroughly after each addition. Stir in the vanilla extract.
04 - Gently fold the sourdough starter into the batter using a spatula until fully incorporated and no streaks remain.
05 - Sift the all-purpose flour, cocoa powder, and fine sea salt together directly into the batter. Fold gently with a spatula until just combined — avoid overmixing to keep the brownies tender.
06 - Pour the batter into the prepared pan and spread it evenly with a spatula. Scatter the mini chocolate chips or candy-coated pieces across the surface, then generously cover with rainbow sprinkles.
07 - Bake for 28 to 32 minutes, or until a toothpick inserted into the center comes out with moist crumbs clinging to it. For a denser, fudgier texture, lean toward the shorter bake time.
08 - Let the brownies cool completely in the pan set on a wire rack. Once fully cooled, use the parchment overhang to lift the slab out and cut into 16 even squares.
# Expert Tips:
01 -
- The sourdough starter adds a barely there tang that makes the chocolate taste deeper and more complex without anyone guessing your secret.
- Those rainbow sprinkles on top turn an already incredible brownie into something people photograph before they eat.
02 -
- Overmixing the batter after adding flour is the fastest way to turn fudgy brownies into cakey ones so stop folding the moment everything looks combined.
- I once pulled them five minutes early because the house smelled done and the center collapsed into goo, which was actually delicious but definitely not what I intended.
03 -
- Weigh your flour instead of scooping it because even a tablespoon too much turns fudgy into dry and there is no recovering from that.
- The sourdough tang is subtle but if you want it more pronounced, let the batter rest in the fridge for an hour before baking and the flavor will deepen noticeably.