1 c. shortening
2 c. sugar
2 egg yolks
2 tsp. vanilla
1 c. cocoa
1 c. hot water
1 c. sour milk
2 tsp. baking soda
1 tsp. salt
3 3/4 c. flour

Mix and drop on cookie sheet spreading a little when dropping. Bake at 450 degrees.

FILLING:

2 egg whites
2 tsp. vanilla
4 tbsp. flour
4 tbsp. milk
1 c. shortening
1 c. confectioners' sugar

Beat until fluffy with mixer. Put between cookies.