Preheat oven to 350°F. Line cupcake pan with paper or foil liners.
In the bowl of an electric mixer, combine thee sugar, flour, cocoa, baking powder, baking soda and salt.
Add the eggs, milk, oil and vanilla and beat on medium speed for 2 minutes.
Stir in the boiling water. The batter will be thin.
Pour batter into each cupcake liner, filling 2/3 full.
Bake for 22-25 minutes or until an inserted toothpick comes out clean.
Turn out and cool onto a wire cooling rack.
While cupcakes are cooling, prepare the frosting.