First you take a Dark Chocolate Duncan Hines cake mix and follow the directions except for the adding oil part, instead of oil just add 1/2 cup Hellman’s Mayonnaise. Bake per package directions.
For the Homemade frosting take 1 stick room temperature butter or margarine and 1 tsp vanilla and about 2- 1/2 cups confectionary sugar (powdered sugar) , a little salt (2 or 3 shakes) , a little tiny bit of milk just enough to moisten and get the frosting creamy.
Frost cupcakes when completely cooled. Nothing like fresh bakery, ever. Makes 30 cupcakes (2 and 1/2 dozen)