1 lb. confectioner's sugar
1/2 c. whole milk

Mix in large bowl by hand until smooth. Microwave on high 6 minutes. Watch closely during last 2 minutes, open door and stir when batter boils to top, set aside. Remove lid of 16 ounce jar peanut butter and place in microwave for 60 seconds on high. Remove lid of 7 ounce jar of marshmallow and place in microwave for 40 seconds on high. Stir all together and spread in buttered pan.

Options: Ground walnuts, milk chocolate chips. Let stand at room temperature until soft.