From the back of the Western Family cocoa can…

1/2 C + 2 T butter or margarine
1 C sugar
1 t vanilla
2 eggs
6 T cocoa
1/2 C sifted all-purpose flour
1/2 C chopped walnuts

Preheat oven to 325 F. Cream butter, sugar and vanilla; beat in eggs. Blend in cocoa. Stir in flour and nuts. Bake in greased 8×8x2 pan for 30 to 35 minutes. Cool and cut in squares.

(substituted 1/4 C butter plus 1/8 C yogurt and 1/8 C mayo for the butter)