Prep: Preheat oven to 350°F. Take eggs, milk, and butter out of the fridge so they come to room temp. Grease or spray a 9×13‑inch pan. Sift the cocoa powder. Set aside.

In a large bowl, whisk together 1 ¾  cup all‑purpose flour, 2 cups granulated sugar, ¾  cup sifted unsweetened cocoa powder, 2 ½  teaspoons baking powder, ½  teaspoon baking soda, and 1 teaspoon salt. Set aside.

In a medium bowl, whisk 2 eggs, 1 cup milk, ½  cup vegetable oil, and 2  teaspoons vanilla extract until blended.

Pour the wet mixture into the large bowl with dry ingredients, then stir until just combined.

Add 1 cup of hot water OR hot coffee and whisk just until smooth. Batter will be runny.

Pour into cake pan and bake 30–35  minutes, until a toothpick or knife edge comes out clean.

Cool completely before frosting.

Prep: Set the tablespoon of milk and butter out to come to room temp if you haven’t already. Sift the cocoa powder.

In a large mixing bowl, beat 1 cup softened butter until creamy.

Add 1 cup of powdered sugar and 1 Tablespoon of milk at a time, beating until smooth. Repeat until all 3 cups of powdered sugar and all 4 Tablespoons of milk are incorporated.

Add ½ cup sifted cocoa powder and 1 teaspoon vanilla extract, then beat until light and fluffy.

Spread over the fully cooled cake.