2/3 c. butter
2/3 c. chunky peanut butter
6 c. confectioners' sugar
1/3 c. milk
1 tbsp. vanilla

In 3-quart glass or microwave bowl, place butter and peanut butter. Microwave on high 1 1/2 to 2 minutes until butter melts. Stir. Add remaining ingredients. Stir until lumps of sugar disappear. Microwave on high 1 to 1 1/2 minutes until softened, but not bubbly. Stir. Pour into buttered 9-inch square baking pan. Cover, refrigerate 1 hour. Store in refrigerator.