• Preheat your oven to 350°F (177°C). Prepare three 8-inch round cake pans by greasing and flouring them; lining the bottoms with parchment paper is also recommended for easy removal.
• In the mixing bowl, combine the dry ingredients: flour, cocoa powder, granulated sugar, baking powder, baking soda, salt, and instant espresso granules. Whisk together until well-blended.
• Add the eggs, vegetable oil, vanilla extract, and ¼ cup of the hot water to the dry ingredients. Mix on medium speed for about 2 minutes, ensuring you scrape down the sides of the bowl occasionally, as the batter will be thick.
• With the mixer set to low, gradually pour in the remaining 1 cup of very hot water. Continue mixing for about 30 seconds until fully combined; the batter will become thin.
• Divide the batter evenly among the three prepared cake pans. Lightly tap each pan on the countertop a few times to release any air bubbles.
• Bake for 22-24 minutes or until a wooden skewer or toothpick inserted into the center comes out clean or with just a few moist crumbs attached. Allow the cake layers to cool in their pans on a wire rack for 10 minutes before gently turning them out to cool completely.

For the Chocolate Buttercream

• Start by creaming the slightly softened butter until smooth and fluffy. Add the vanilla extract and mix until combined.
• Gradually add half of the confectioners’ sugar and cocoa, followed by most of the milk or cream. Beat on medium speed until everything is incorporated, scraping the sides of the bowl as needed.
• Add the remaining confectioners’ sugar, cocoa, milk, and salt, and continue beating on medium speed for an additional 3-4 minutes. Reduce the mixer speed to low and beat for 1-2 minutes to eliminate air bubbles, creating a smooth and creamy frosting texture.
• The frosting yields approximately 4 ½ to 5 cups. Adjust consistency as needed by adding more sugar if too thin or more milk if too thick.