Preheat oven to 350 degrees. Grease and flour 2 nine inch round baking pans.
In a large bowl, stir together sugar, flour, cocoa, baking powder, baking soda and salt.
Add the eggs, milk, oil and vanilla. Using a hand mixer, mix for 2 minutes on medium speed. Stir in the boiling water. Mix for another minute. Batter will be thin.
Pour cake batter evenly into the greased and floured pans.
Bake 30-35 minutes in the preheated oven until the cake is done. (Use a toothpick to test).
Cool the pans for five minutes, then remove to a wire rack to cool the cakes to room temperature.
Recipe by Katie Talks Carolina at http://katietalkscarolina.com/best-reeses-peanut-butter-cup-cake-recipe/