Preheat Oven: Heat oven to 350°F. Grease and line three 8inch cake pans with parchment paper. Grease the paper and sides of the pans as well. You can also use two 9inch pans.
Mix Dry Ingredients: In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, salt, and optional espresso powder.
Combine Wet Ingredients: In another bowl, mix the eggs, vegetable oil, buttermilk, sour cream, and vanilla extract until smooth.
Blend Ingredients: Pour the wet ingredients into the dry ingredients and whisk until just combined. Add the hot coffee and mix until smooth. The batter will be thin.
Divide and Bake: Divide the batter evenly among the cake pans. Tap the pans on the counter to release air bubbles. Bake for 3035 minutes or until a toothpick comes out clean.
Cool: Let the cakes cool in the pans for 15 minutes, then transfer to a rack to cool completely. If not frosting immediately, wrap in plastic and freeze.