Potato Brownies

1/4 c. butter or shortening
1 c. brown sugar
1/2 c. cold mashed potatoes
1 egg
2 oz. unsweetened chocolate, melted
1 tsp. vanilla
1 1/2 c. flour
1/2 tsp. salt
1/2 tsp. baking soda
3/4 c. buttermilk
1/2 c. nuts (opt.)

Cream shortening (or butter) with sugar. Beat in potatoes, egg, vanilla and melted chocolate. Add dry ingredients alternately with buttermilk. Stir in nuts. Pour into greased 9×11-inch pan. Bake at 350° for 15 to 20 minutes.