Ingredients
Scale
- 1/2 cup 2oz, 60g unsweetened cocoa powder
- 1 1/2 teaspoons baking soda
- 1/2 teaspoon table salt
- 1/2 cup 4fl.oz, 125ml brewed coffee hot
- 1/2 cup 4fl.oz, 125ml vegetable or canola oil
- 1 cup 8fl.oz, 250ml buttermilk
- 2 teaspoons vanilla extract
- 2 eggs room temperature
- 1 3/4 cups 12.3oz, 350g granulated sugar
- 2 cups 10.6oz, 300g all purpose flour
- 6 tablespoons unsalted butter softened
- 1/8 teaspoon table salt
- 2 cups 9.2oz, 260g powdered sugar
- 1 teaspoon vanilla extract
- 1-2 tablespoons buttermilk
- 1/2 cup 4fl.oz, 125ml buttermilk
- 2 tablespoons corn syrup
- 1/2 cup 2oz, 60g unsweetened cocoa powder
- 1/2 cup 4oz, 115g unsalted butter
- 1/4 teaspoon table salt
- 4 cups 18.3oz, 520g powdered sugar
- 1 teaspoon vanilla extract
Instructions
- Prep the oven by preheating it to 350°F (177ºC) and spraying a 9×13-inch cake pan with nonstick spray. Set aside.
- In a mixing bowl, combine cocoa powder, baking soda, and salt. Add hot coffee and mix gently for about 15–20 seconds until smooth.
- Incorporate the oil and buttermilk, mixing until well combined. Beat in vanilla and eggs on medium speed until smooth, around 1–2 minutes.
- Add granulated sugar and flour, mixing on medium speed just until smooth. Expect a thinner consistency for the batter.
- Pour the batter into the prepared pan and bake for 30–35 minutes. The cake is done when the center springs back and a toothpick comes out with a few moist crumbs.
- Allow the cake to cool in the pan for 20–30 minutes, then transfer it to the freezer and chill for 20 minutes.
- While chilling, beat butter on high speed until creamy. Add salt, powdered sugar, vanilla, and one tablespoon of buttermilk, mixing from low to medium-high until fluffy. Adjust with additional buttermilk if needed.
- Fill a piping bag with the buttercream and pipe thick ridges across the short side of the cake, leaving some space between each row.
- Freeze the cake again for about 40 minutes until the buttercream ridges firm up.
- In a saucepan, combine buttermilk, corn syrup, cocoa powder, butter, and salt over medium-low heat. Stir until the butter melts and mixture bubbles slightly.
- Remove from heat and whisk in powdered sugar and vanilla until smooth and glossy. Allow to cool slightly before frosting.
- Pour the warm fudge frosting over the cake, ensuring the buttercream ridges are covered. Tilt the pan to spread evenly without a spatula.
- Refrigerate until frosting is set, then let slices sit at room temperature for 15–20 minutes before serving.
Notes
For added flavor, consider substituting coffee with espresso.
If the cake is too thick, you can add a little more buttermilk to achieve the desired consistency.
Let the cake cool completely before frosting to prevent melting.
Nutrition
- Serving Size: 1 slice
- Calories: 400
- Sugar: 36g
- Sodium: 300mg
- Fat: 18g
- Saturated Fat: 8g
- Unsaturated Fat: 8g
- Trans Fat: 0g
- Carbohydrates: 54g
- Fiber: 2g
- Protein: 3g
- Cholesterol: 60mg
Nutritional information is an estimate. The nutritional values for your final dish may vary based on measuring differences and products used.