Prepare the Pans:

1. Preheat your oven to 350°F (175°C). Grease two 9-inch round cake pans with butter or cooking spray, then line the bottoms with parchment paper circles. Grease the parchment paper as well. This double-greasing ensures easy cake removal.

Mix Dry Ingredients: 2. In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt until well combined and there are no lumps. This step is important for evenly distributing the leavening agents.

Combine Wet Ingredients: 3. Add the eggs, buttermilk, oil, and vanilla extract to the dry ingredients. Using an electric mixer on medium speed, beat for about 2 minutes until smooth and well combined. The batter will be thick at this point.

Add Hot Coffee: 4. Carefully stir in the hot coffee with a spatula or wooden spoon. The batter will become very thin—this is completely normal and exactly what you want! The thin batter is the secret to the cake’s moist texture.

Bake: 5. Divide the batter evenly between the prepared pans, using a kitchen scale for precision if you have one. Tap the pans gently on the counter a few times to release any air bubbles.

6. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out with just a few moist crumbs (not wet batter). The cakes should spring back when lightly touched. Avoid overbaking or the cake will be dry.

Cool: 7. Remove from the oven and let the cakes cool in the pans for 10 minutes. Then carefully run a knife around the edges and invert onto cooling racks. Peel off the parchment paper and let cool completely before frosting—this usually takes about 1-2 hours.

Make the Frosting: 8. While the cakes cool, prepare the frosting. Beat the softened butter on medium-high speed for 3-4 minutes until pale and fluffy.

9. Sift together the powdered sugar and cocoa powder to remove lumps. Add to the butter gradually, mixing on low speed to avoid a sugar cloud.
10. Add the heavy cream, vanilla, and salt. Beat on low speed until combined, then increase to high speed and beat for 3-4 minutes until light and fluffy. If the frosting seems too thick, add more cream one tablespoon at a time. If too thin, add more powdered sugar.

Assemble: 11. Place one cake layer on your serving plate or cake stand. Spread about 1 cup of frosting evenly over the top. Place the second layer on top, pressing down gently.

12. Use the remaining frosting to cover the top and sides of the cake. Start with a thin crumb coat if desired, refrigerate for 15 minutes, then apply a final thick layer of frosting. Use an offset spatula for smooth sides and swirls on top.