PREPARATION
Combine boiling water, butter, sugar, and cocoa powder in a bowl. Beat the mixture until sugar dissolves.
Add the sifted flour, salt, baking powder and baking soda alternately with the beaten egg, sour cream, and vanilla essence.
Grease and lightly flour the cupcake moulds. Fill the moulds with the above mixture till they are about half full.
Bake at 350°C for 25 minutes.
Frost with your favorite frosting..