Put Marshmallow Cream and Peanut Butter in a bowl. Start adding Simple Syrup maybe about 1/2 cup. Mix and add the Simple Syrup until it is as thin as cake batter. It will get thick when you store it in the fridge. Use this as a yummy Ice Cream topping!! Any leftover Simple Syrup can be stored in the fridge for thinning if it is too thick.