8oz(225 g) semi-sweet chocolate chips or chopped bar chocolate
½cup(45 g) unsweetened cocoa powder
½cup(100 g) cane sugar
½cup(110 g) dark brown sugar, packed
2large eggs + 1 egg yolkroom temperature
2tsppure vanilla extract
½cup(125 g) sourdough discard (100% hydration)
¾cup(90 g) fresh-milled hard white wheat flour, sifted
½tspsalt
½tspbaking soda
½cup(90 g) milk chocolate chips (to fold in)
flaky sea salt for topping (optional)
Instructions
Preheat the oven and prep the pan
Preheat the oven to 350°F (175°C).
Line a 9×9-inch baking pan with parchment paper.
Melt chocolate base
In a saucepan over low heat, melt the butter and 8 oz chocolate chips together until smooth. Remove from heat and whisk in the cocoa powder. Let cool slightly.
Whip eggs & sugar
In a stand mixer bowl, beat the eggs, yolk, cane sugar, and brown sugar on medium-high speed for 7–8 minutes, until thick, pale, and ribbony. This step is key for achieving the shiny, crackly top.
Combine wet ingredients
Add the vanilla and sourdough discard to the egg mixture and gently fold to combine. Then pour in the cooled chocolate mixture, folding gently until no streaks remain.
Mix dry ingredients and combine
In a small bowl, whisk together the flour, salt, and baking soda. Sift into the wet batter and fold gently until just combined. Do not overmix.
Fold in chips
Stir in ½ cup milk chocolate chips for little melty pockets of sweetness.
Bake
Spread the batter evenly in the prepared pan. Bake for 32–38 minutes, until the edges are set and the center is just barely underdone (a toothpick should come out with moist crumbs, not dry).
Cool & finish
Allow to cool completely in the pan on a wire rack. Sprinkle with flaky sea salt if desired, then slice into squares.
Notes
Baker’s Notes
Sourdough discard: This recipe is designed for discard (unfed starter). It adds moisture and depth without making the brownies sour.
Shiny top: Don’t skip the long whipping step with the eggs and sugar! That’s what creates the signature glossy crust.
Storage: Brownies keep well for up to 4 days at room temp in an airtight container — and the flavor deepens on day 2.