In a medium saucepan, combine sugar, water, and butter and bring to a boil.

Reduce heat to low and then stir in corn syrup; boil for 1 minute more, and then remove from heat.

Stir in peanut butter, marshmallow cream, and vanilla and stir with a wooden spoon until well blended.

Store in a tightly covered container in the refrigerator until ready to use and then let the spread sit out at room temperature until it’s spreadable.