Chocolate Fudge Sourdough Brownies

Decadent, glossy, and intensely chocolatey — sourdough adds complexity to this indulgent classic.

At a Glance

• Loaf Style: Fudgy tray bake

• Skill Level: Beginner-friendly

• Total Time: ~12–18 hours (includes optional chill)

• Prep Time: ~20 minutes

• Yield: 16 squares (8x8” pan)

• Hydration: N/A

• Bake Temp: 350°F / 175°C

• Baking Vessel: Square baking dish (8x8”)

Ingredients

• 100g sourdough discard (unfed starter)

• 170g dark chocolate (60–70%), chopped

• 115g unsalted butter

• 100g brown sugar

• 100g granulated sugar

• 2 large eggs

• 1 tsp vanilla extract

• ¼ tsp salt

• 35g unsweetened cocoa powder

• 80g all-purpose flour

• Optional: 50g chopped walnuts, espresso powder, or chocolate chunks

Instructions

Melt Chocolate & Butter
1. In a heatproof bowl, melt chocolate and butter together over a double boiler or in short microwave bursts.
2. Stir until smooth and glossy. Let cool slightly.

Mix Wet Ingredients
3. Whisk in brown sugar and granulated sugar until dissolved.
4. Add eggs one at a time, then stir in vanilla and sourdough discard until fully incorporated.

Add Dry Ingredients
5. Sift in cocoa powder, flour, and salt. Stir until just combined.
6. Fold in optional mix-ins like chocolate chunks or nuts.

Rest (Optional)
7. For deeper flavor and fudgier texture, cover and refrigerate the batter for 8–12 hours.
8. If baking immediately, proceed to the next step.

Bake
9. Preheat oven to 350°F / 175°C. Line an 8x8” square pan with parchment.
10. Pour in the batter and smooth the top.
11. Bake for 25–30 minutes, until the edges are set and the center is still slightly glossy.
12. Cool fully in the pan before slicing into squares.

Visual Cues

• Crackly top with a rich, dense center.

• When sliced, the brownies should be moist and glossy with a soft fudge-like crumb.

Why This Works

Sourdough discard brings an understated tang that highlights the richness of chocolate, while also creating a smoother, more structured crumb. The result is a brownie that’s both luxurious and deeply satisfying — every bit as indulgent as it looks.