Cakes-In a large bowl, cream together ½ cup vegetable shortening, 1 cups sugar and 1 egg. Add 1 cup butter milk, 2 cups sifted flour, ½ cup sifted unsweetened cocoa, and 1 tsp salt. Mix well.
Add ½ cup water and 1 tsp. baking soda and mix until smooth.
Filling-Mix 3½ cups confectioner's sugar, 2 tbsp. flour, 1 tsp. vanilla, 1½ tsp. lemon juice, ¼ cup milk, ½ cup vegetable shortening on low speed until blended.
Preheat oven to 350 degrees. Filling-Then mix on high speed until fluffy. Scoop filling on half the cakes, then cover with another cake.