Heat the oven to 350º F. Get two 9-inch cake pans ready by either spraying them with baking spray or by greasing them with butter and dusting with flour.

In a large bowl or the bowl of a stand mixer, combine flour, sugar, cocoa powder, baking powder, baking soda, salt, and espresso powder. Use a whisk to mix everything together, or use the paddle attachment on your mixer to blend the ingredients thoroughly.

Pour the milk, vegetable oil, eggs, and vanilla into the flour mixture. Mix on medium speed until everything is well blended. Lower the speed and slowly add the boiling water to the batter, ensuring it is thoroughly combined.

Evenly divide the cake batter between the two prepared pans. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

Take the cakes out of the oven and let them cool in the pans for about 10 minutes. Then, remove the cakes from the pans and allow them to cool completely on a wire rack.

Spread the Chocolate Buttercream Frosting generously over the cake.