Cream 1/2 cup of shortening and reguarl sugar together.
Add the 2 egg yolks and mix until light colored
In another bowl, sift together the cocoa, flour, baking powder, soda and 1 tsp salt.
Mix the milk and 1 tsp of vanilla. Add alternately to the creamed mixture with the dry ingredients, mixing in between.
Drop by teaspoonfuls onto an ungreased (I prefer to use parchment paper) cookie sheet(s). Make an even amount. You need to cookies for each Whoopsie!
Bake at 375 degrees for about 8 to 10 minutes. Depends on how big of a cookie you want to make.
While the cookies are cooling, make the filling by first beating the egg whites until stiff. Fold in a bit of the confectioner's sugar. Cream the 1/2 cup of shortening, then add the rest of the confectioner's sugar to the shortening. Add the 1/4 tsp of salt and 1 tsp of vanilla.
Fold in the beaten egg whites.
Put your cooled cookies together with filling and wrap in waxed paper.