Whoopie Pies

Name: Whoopie Pies
Ingredients: 1 1/2 tsps baking soda; 1/4 cup butter; 1/2 cup cocoa; 1 1/2 cups confectioners' sugar; 1 egg; 2 cups flour; 1 cup marshmallow fluff; 1 cup milk; 1/2 tsp salt; 1/2 cup shortening; 1 cup sugar; 1/2 tsp vanilla