Step 1: Prepare Cake Batter

1. Preheat oven to 350°F (175°C). Grease and line two 8-inch cake pans.
2. In a bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.
3. In a separate bowl, mix coffee, oil, eggs, and vanilla.
4. Gradually combine wet ingredients with dry, stirring until smooth. Do not overmix.
5. Divide batter evenly between prepared pans.

Step 2: Bake the Cake

1. Bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean.
2. Cool cakes in the pans for 10 minutes, then transfer to a wire rack.

Step 3: Make the Coffee Buttercream

1. Beat butter until creamy and fluffy.
2. Add powdered sugar gradually, mixing on low speed.
3. Stir in dissolved coffee and vanilla. Mix until smooth.
4. Add cream until the frosting reaches a spreadable consistency.

Step 4: Optional Ganache Topping

1. Heat heavy cream until just simmering.
2. Pour over chopped chocolate and let sit for 1 minute.
3. Stir until smooth and let cool to room temperature.

Step 5: Assemble the Cake

1. Place one cake layer on a plate. Spread with buttercream.
2. Add second cake layer and frost top and sides.
3. Drizzle with ganache if using.