Equipment
Ingredients
Cake Batter
- 115 g unsweetened chocolate, chopped
- 315 g all-purpose flour
- 6 g baking soda
- 2 g baking powder
- 3 g salt
- 170 g unsalted butter, room temperature
- 300 g granulated sugar
- 2 eggs, large, room temperature
- 5 ml vanilla extract
- 300 ml buttermilk, room temperature
Classic Fudge Frosting
- 225 g unsalted butter, softened
- 400 g powdered sugar, sifted
- 60 g cocoa powder, unsweetened, sifted
- 60 ml heavy cream
- 5 ml vanilla extract
- 1 g salt
Nutrition (per serving)
Method
Preheat your oven to 175°C (350°F). Grease three 9-inch round cake pans with butter, line the bottoms with parchment paper, grease the parchment, and dust with flour, tapping out the excess.
Melt the chopped unsweetened chocolate in a heat-proof bowl over simmering water or in the microwave (30-second bursts). Stir until smooth and set aside to cool slightly (it should be fluid but not hot).
Sift together the flour, baking soda, baking powder, and salt into a medium bowl. In a separate measuring jug, combine the room temperature buttermilk and vanilla extract.
In the bowl of a stand mixer fitted with the paddle attachment, cream the softened butter on medium-high speed. Gradually add the sugar and continue beating for 3-5 minutes until the mixture is pale, light, and fluffy.
Add the eggs one at a time, beating well after each addition to ensure they are fully emulsified. Scrape down the sides of the bowl as needed.
Reduce mixer speed to low. Add the dry ingredient mixture in three parts, alternating with the buttermilk mixture in two parts, starting and ending with the dry ingredients. Mix just until the flour disappears.
Pour the cooled melted chocolate into the batter. Mix on low speed or fold by hand until the chocolate is evenly distributed and the batter is a uniform color.
Divide the batter evenly among the prepared pans. Smooth the tops with a spatula. Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean.
Cool the cakes in their pans on a wire rack for 10 minutes. Then, invert them onto the rack, peel off the parchment, and let them cool completely before frosting.
Make the frosting: Beat the butter until creamy. Gradually add the powdered sugar and cocoa powder. Add the heavy cream, vanilla, and salt, and whip on high speed until light and fluffy (about 3 minutes). Spread between layers and over the top and sides of the cooled cake.
Chef's Notes
- Temperature management is critical: if your buttermilk or eggs are cold, the melted chocolate will seize into flakes rather than blending smoothly into the batter.
- Unsweetened chocolate (100% cacao) is essential here—do not substitute semi-sweet, as it alters the sugar ratio and the cake's distinctive deep flavor profile.
- This cake improves in flavor and moisture if allowed to sit at room temperature for a few hours after frosting before serving.
Storage
Refrigerator: 4 days — Store in an airtight cake carrier to prevent drying. Bring to room temperature before serving for best texture.
Freezer: 3 months — Freeze unfrosted layers tightly wrapped in plastic. Frosted cake can be frozen if flash-frozen first.
Reheating: Serve at room temperature.
