Potato Cookies

1/2 c. butter or margarine
1 c. packed brown sugar
1 tsp. vanilla
1 lg. egg
2 sq. unsweetened chocolate
1/2 c. mashed potatoes
1/2 c. nuts
1 1/2 c. flour
1/2 tsp. salt
1/2 tsp. baking powder
3/4 c. buttermilk

Cream butter and sugar; add egg and vanilla. Blend in chocolate, potatoes and nuts. Add dry ingredients with the buttermilk. Drop by teaspoon on cookie sheet and bake at 375° for 10 to 12 minutes.