Whoopie Pies - cooking recipe

Ingredients

1 c. shortening
2 c. sugar
2 whole eggs
2 egg yolks (save whites)
2 tsp. vanilla
2 tsp. boiling water
2 tsp. baking powder
2 tsp. baking soda
1 c. cocoa
1 c. sour milk
1 c. hot water
3 3/4 c. flour

Preparation

A small amount of vinegar or lemon juice will sour milk.