Nanny's Chocolate Potato Cake Recipe

My grandmother Abby Brown, Nanny uses to make this cake when ever she had leftover mashed potatoes.  My sisters, cousins, parents, aunts and uncles would finish before it could cool off.

3/4 cup butter or margarine softened

2 cups sugar

4 eggs, separated

1 cup mashed potatoes

1/2 cup water

1 teaspoon vanilla extract

2 cups all-purpose flour

3 tablespoons baking cocoa

2 teaspoons baking powder

1 cup chopped walnuts

Directions: 

In a large mixing bowl, cream the butter and sugar.

Add the egg yolks, potatoes, water and vanilla ~ mix well.

Combine the flour, cocoa and baking powder ~ add to the creamed mixture.

In a small mixing bowl beat egg whites until stiff peaks form into batter.

Add chopped walnuts.

Pour into a greased 13-in. x 9-in. x 2-in. baking pan.

Bake at 350 degrees F for 30-35 minutes or until a toothpick inserted near the center comes out clean.

Cool on a wire rack.

Dust with powered sugar and chocolate syrup.