Whoopie Pie

1/2 cup butter
1 1/2 cup sugar
1/2 cup sour milk (add a touch of vinegar)
1/2 cup cocoa
1 tsp baking soda
2 2/3 flour
1 tsp vanilla
2 eggs
1/2 cup water
1 tsp salt

Cream butter and sugar. Add remaining ingredients. Mix together and drop by tbsp like cookies onto a cookie sheet. Bake at 350* for 13 minutes.

Filling
3/4 cup milk
3/4 cup butter
1 tsp vanilla
3 tbsp flour
3/4 tbsp sugar
1/2 tsp mint

Cook milk and flour until thick. Cream butter and sugar. Add vanilla and cooled milk mixtures. Beat on high until light and creamy. Spread between two cookies.