It’s a spoonable sauce that tastes just like melted marshmallows. It comes in a jar and is typically located with the ice cream toppings. If your store doesn’t carry it, you can find it online or make a substitute at home. Combine marshmallow creme or fluff with 1 to 2 tablespoons of water and microwave for about a minute. This should create the perfect consistency for pouring over the s'mores poke cake.