Peanut Butter Fudge

1 box powdered sugar, sifted
1/2 cup cocoa
6 Tablespoons butter
1 Tablespoon vanilla
1/4 teaspoon salt
1 cup shopped nuts
2-3 Tablespoons peanut butter

Mix together all ingredients except nuts and peanut butter in double boiler until butter melts.  Then add nuts and peanut butter; mix well.  Pour into 8×8 inch buttered pan. Cool in refrigerator.