one-bowl chocolate cake with fluffy buttercream frosting - Pass the Cookies

Ingredients

• 3/4 cup butter
• 3 cups powdered sugar, sifted
• 1-4 tablespoons heavy cream
• 1/2 teaspoon vanilla
• pink or red food coloring, optional
• sprinkles, optional
• 1/2 cup hot coffee
• 6 tablespoons butter
• 2 eggs
• 3/4 cup milk
• 2 teaspoons vanilla
• 1 cup sugar
• 3/4 cup flour
• 1/2 cup unsweetened cocoa powder (I use dark)
• 1 1/2 teaspoons baking powder
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt
• 4 ounces dark or semi-sweet chocolate, finely chopped*