Chocolate Potato Cake

2 c. sugar
1 c. shortening
4 eggs
1 c. warm unseasoned mashed potatoes
1/2 c. cocoa
2 c. flour
1 c. buttermilk
1 tsp. baking soda
1 tsp. vanilla
1 c. nuts, optional

Cream shortening and sugar. Add eggs and beat until light and fluffy.
Combine flour, cocoa and baking soda.
Stir mashed potatoes into sugar mixture.
Add flour mixture alternately with buttermilk, starting and ending with dry ingredients.
Stir in nuts, if desired. Pour into a greased and floured 9x13 pan.

Bake at 350 degrees for 35 to 40 minutes. Cool and frost