Step 1: Preheat the Oven. Preheat your oven to 350°F (175°C).
Step 2: Prepare the Cake Pans. Grease your 9-inch cake pans and line the bottoms with parchment paper.
Step 3: Mix Dry Ingredients. Combine flour, sugar, cocoa powder, baking soda, baking powder, and salt in a large bowl.
Step 4: Combine Wet Ingredients. Mix buttermilk, oil, eggs, and vanilla in another bowl using an electric mixer.
Step 5: Incorporate Coffee. Gradually add warm brewed coffee to the wet mixture until combined.
Step 6: Combine Wet and Dry Mixtures. Slowly pour the wet ingredients into the dry ingredients and mix until just combined.
Step 7: Bake the Cake. Divide the batter among the pans and bake for 30-35 minutes. Allow to cool.
Step 8: Prepare the Frosting. Beat butter and cream cheese until creamy, then add cocoa powder, vanilla, and sugar alternating with cream.
Step 9: Assemble the Cake. Layer the cakes with frosting in between and frost the top and sides.
Step 10: Garnish. Sprinkle mini chocolate chips on top and drizzle with melted chocolate if desired.