2 lb. powdered sugar
1/2 c. cocoa
12 oz. peanut butter
3 1/3 sticks butter, melted
2 tsp. vanilla

Mix sugar and cocoa in a large bowl, make a well. Melt peanut butter and butter together and add vanilla. Add mixture to sugar and cocoa. Knead well. Add nuts, if desired. Spread in a 9x13 inch greased pan and cut into squares when hardened.