Step 1: Preheat and Prepare

Preheat your oven to 350°F (175°C) without using the fan setting. Grease three 8-inch round cake pans with butter and line the bottoms with parchment paper for easy release.

Step 2: Mix the Dry Ingredients

In a large mixing bowl, whisk together the flour, baking powder, baking soda, granulated sugar, brown sugar, and salt until no lumps remain. This ensures an even distribution of ingredients for a perfectly balanced cake.

Step 3: Combine the Wet Ingredients

In a separate bowl, whisk the eggs, vegetable oil, buttermilk, and sour cream until smooth and fully combined. The buttermilk and sour cream add moisture and richness to the cake.

Step 4: Blend Wet and Dry Ingredients

Add the dry ingredients to the wet mixture in two additions, gently whisking and folding until just combined. Avoid overmixing to prevent a dense texture.

Step 5: Make the Cocoa Mixture

In a small bowl, combine the cocoa powder and instant coffee. Pour in the boiling water and whisk until smooth and shiny. This step enhances the chocolate flavor and creates a silky consistency.

Step 6: Finalize the Batter

Pour the cocoa mixture into the batter and gently fold until fully incorporated. Divide the batter evenly among the prepared pans.

Step 7: Bake the Cakes

Bake for 22–24 minutes, or until a toothpick inserted into the center comes out with light, moist crumbs attached. Let the cakes cool in the pans for 20 minutes, then transfer them to a wire rack to cool completely. For best results, refrigerate the cakes for 1 hour before assembling.

Step 8: Prepare the Chocolate Fudge Frosting

1. In a saucepan, melt the semi-sweet chocolate and corn syrup over low heat, stirring constantly until smooth. Set aside to cool slightly.
2. In the bowl of a stand mixer, combine the cream cheese, sifted cocoa powder, powdered sugar, and salt. Use the paddle attachment to mix on medium speed for 1–2 minutes, until creamy. Scrape the bowl as needed.
3. Add the heavy cream and mix on low speed until the frosting becomes light and fluffy. Avoid overmixing.
4. Slowly pour the melted chocolate into the frosting while whisking on low speed. The frosting will become runnier due to the warm chocolate. Let it cool at room temperature for 30 minutes or in the fridge until spreadable. If it becomes too firm, microwave 1 cup of frosting for a few seconds and whisk it back in.

Assembly Instructions

1. Trim the Layers: Once the cakes and frosting have cooled, use a large serrated knife to carefully trim off the domed tops of the cakes for an even surface.
2. Layer the Cake: Place one cake layer on a serving plate and spread a generous amount of frosting on top. Repeat with the remaining layers, stacking them neatly.
3. Crumb Coat: Apply a thin layer of frosting (crumb coat) over the entire cake to seal in crumbs. Refrigerate for 20 minutes.
4. Final Frosting: Spread the remaining frosting evenly over the cake for a smooth finish.

Serving Suggestions

This chocolate fudge cake is best enjoyed at room temperature. For a professional touch, use a blow dryer on the lowest setting to gently wave it 1 foot away from the cake for a glossy, shiny appearance.