Prep: 1. Bring all butter and eggs to room temperature (or soften butter in the microwave). 2. Preheat the oven to 350. Grease the bottom and sides of two 9-inch round cake pans with butter. Make: 1. Whisk the flour, baking powder, and salt together; set aside. 2. Using an electric mixer, cream 1 cup butter and sugar on medium-high speed for about 4 minutes, until the mixture is light and fluffy. Scrape down the sides and bottom of the bowl. 3. Add the eggs, one at a time, beating to incorporate before adding the next and scraping the bowl as needed. Mix in 2 teaspoons vanilla. 4. With the mixer on low speed, add half of the dry ingredients, then the 1 1/4 cup milk, then the remainder of the dry ingredients. 5. Divide the batter evenly between the two prepared pans. Bake for 30 to 35 minutes, until a toothpick comes out clean when inserted into the centers. 6. Transfer the pans to a wire rack to cool for 20 minutes before flipping the cakes to the wire rack. Allow the cakes to cool completely before frosting. Frosting: 1. Using an electric mixer, cream 1 cup butter. Sift in cocoa powder and mix on medium until well-combined. 2. Add powdered sugar and milk to cocoa mixture by adding 1 cup of powdered sugar followed by about a tablespoon of milk. After each addition has been combined, turn mixer onto a high speed for about a minute. Repeat until all sugar and milk have been added. 3. Add 1 1/2 teaspoons vanilla extract and coffee grounds and combine well.
Make sure the coffee grounds for the frosting are finely ground.