Chocolate Buttermilk Cake Recipe

Prepare oven and pans

Preheat oven to 350°F (175°C). Grease a 9-inch round cake pan (or a 9x2-inch cake pan) and line the bottom with parchment. Lightly grease parchment and dust with a thin layer of flour or cocoa, tapping out excess.

Combine dry ingredients

In a large bowl, whisk together 2 cups all-purpose flour, 1 3/4 cups granulated sugar, 3 tablespoons unsweetened cocoa powder, 1 1/2 teaspoons baking soda, 1/2 teaspoon baking powder, and 1 teaspoon fine salt until evenly distributed.

Mix wet ingredients

In a separate bowl or large measuring cup, whisk or beat 1/2 cup melted and cooled unsalted butter with 2 large eggs until smooth. Add 1 cup buttermilk and 2 teaspoons vanilla extract and whisk to combine. Temper mixture by ensuring the butter is not too hot so it doesn't cook the eggs.

Combine wet and dry

Make a well in the center of the dry ingredients and pour in the wet mixture. Stir gently with a spatula or wooden spoon until mostly incorporated and no large streaks of flour remain; do not overmix.

Add coffee for texture and flavor

Stir in 3/4 cup strong brewed coffee or hot water (hot but not boiling) in two additions, mixing until smooth. The batter will be fairly thin — that is normal and produces a moist crumb.

Bake

Pour batter into prepared pan and smooth the top. Bake in preheated 350°F (175°C) oven for 30–38 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs (not raw batter). Rotate the pan halfway through baking for even browning if your oven has hot spots.

Cool

Remove cake from oven and set on a wire rack. Let cake cool in the pan for 10–15 minutes, then run a knife around the edge, invert onto the rack, remove parchment, and turn right-side-up. Cool completely before glazing (about 1 to 1.5 hours).

Warm cream and combine

Place 3 oz semisweet chocolate chips in a heatproof bowl. Heat 1/4 cup heavy cream until steaming (do not boil) and pour over the chocolate. Let sit for 1–2 minutes to soften the chocolate.

Finish glaze

Stir the chocolate and cream together until smooth. Add 1 tablespoon unsalted butter and 1 teaspoon light corn syrup (or honey) and stir until glossy. Stir in 1/4 teaspoon sea salt if using. If glaze is too thick, add up to 1 teaspoon warm cream; if too thin, let it cool a few minutes to thicken slightly.

Glaze the cake

Place cooled cake on a wire rack set over a baking sheet. Pour the glaze over the center of the cake and spread gently with an offset spatula, letting it drip down the sides for an even coating. Allow glaze to set at room temperature about 20–30 minutes before slicing.