3 cups brown sugar
4 eggs
2 tsp cinnamon
1 tsp nutmeg
1 tsp soda
3 cups flour
3 cups oatmeal
Cream shortening, sugar and eggs. Add remaining ingredients. Roll into small balls and flatten on cookie sheet. Bake at 350*F. When cool, put 2 cookies together with filling.
Filling:
2 egg whites
2 tsp vanilla
4 Tbsp milk
4 cups icing sugar
1 cup Crisco
Beat egg whites until foamy. Add vanilla, milk and 2 cups icing sugar. Beat thoroughly and add remaining icing sugar and Crisco. Beat until smooth and fluffy.
(I realize that this isn't the most detailed recipe ever, but I just copied it the way it's written. I recommend not over-baking the cookies.)