Chocolate Fudge Cake with Orange

CAKE:
1 cup flour
4 t. baking powder
1/4 cup softened butter
4 eggs, separated
1 t. vanilla
1/2 t. nutmeg
1 cup unsweetened cocoa
1/2 t. salt
1-1/2 cups sugar
2 cups milk
1 t. grated orange rind

Lightly grease and flour 2 9" round pans.
Sift together flour, cocoa, baking powder and salt.
In a large bowl cream together butter and sugar. Add egg yolks, on at a time, beating well after each is added.
Gradually add flour mixture and milk alternately. Mix well.
Stir in vanilla, nutmeg and orange rind.
Beat egg whites until stiff; fold into batter.
Pour into pans and bake at 350 degrees for 35 minutes

ICING:
1 cup sour cream
8 oz. melted semi-sweet chocolate
Pinch of salt

1 t vanilla