Fudge Cake Slice Recipe

Prepare

Preheat the oven to 350°F (175°C). Lightly butter an 8x8-inch square baking pan and line it with parchment, leaving a 1-inch overhang at two opposite sides for easy removal.

In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt until evenly combined and free of lumps.

In a separate medium bowl, whisk the eggs, buttermilk, vegetable oil, and vanilla extract until smooth.

Pour the wet ingredients into the dry ingredients and stir gently until mostly combined. Gradually add the hot water and stir until the batter is smooth and slightly thin — this helps produce a moist, fudgy crumb.

Pour the batter into the prepared pan, smoothing the top with a spatula. Tap the pan lightly on the counter to release air bubbles.

Bake in the preheated oven for 25–30 minutes, or until the edges are set and a toothpick inserted in the center comes out with moist crumbs (not wet batter). Avoid overbaking to keep fudgy texture.

Remove the cake from the oven and let it cool in the pan on a wire rack for 15 minutes. Using the parchment overhang, lift the cake from the pan and transfer it to the rack to cool completely before adding the fudge filling (about 1 hour).

Place the chopped dark chocolate in a heatproof bowl.

In a small saucepan, combine the heavy cream, butter, and light corn syrup (if using). Warm over medium heat until it just begins to simmer at the edges — do not boil.

Pour the hot cream mixture over the chopped chocolate. Let sit undisturbed for 1–2 minutes to soften the chocolate.

Gently stir from the center outward until the chocolate is completely melted and the mixture is glossy and smooth. If using, sift in the confectioners' sugar and stir until incorporated. Stir in the pinch of salt to balance sweetness.

Allow the ganache to cool at room temperature, stirring occasionally, until it thickens to a spreadable fudge-like consistency (about 20–30 minutes). For faster thickening, place the bowl in the refrigerator and check every 5 minutes to avoid over-hardening.

If the cake has domed, level it with a serrated knife so the top is flat. Place the cooled cake on a cutting board or serving platter.

Spread the thickened ganache evenly over the top of the cake using an offset spatula, leaving the sides clean for a neat slice. For a thicker fudge layer, reserve some ganache and add a second layer after the first sets for 10–15 minutes.

Let the ganache set at room temperature for about 30 minutes, or place the cake in the refrigerator for 10–15 minutes until the ganache is firm but still sliceable.

Dust the top lightly with powdered sugar just before serving if desired.

Slice into 9 equal squares (3x3) using a sharp knife wiped clean between cuts for neat slices. Serve at room temperature for the best fudgy texture.