Cook your popcorn. (I actually prefer to make stovetop popcorn - tastes so much better!). Remove any unpopped kernels. If you prefer the microwave kind, be sure to get the crispy white or tender white, NOT the buttered flavors, which just get soggy.
Melt the butter in a saucepan over low heat. Swirl the pan to coat.
Add the Peeps and turn heat to medium, stirring until the marshmallows are melted and the mixture is nice and smooth. Keep stirring while they are melting, or the sugar will scorch.
Pour the melted mixtures over your popcorn and gently stir with a silicone spoon.
Dump the sticky popcorn out on waxed paper to cool. Be careful - the marshmallow gets very hot and can result in burned fingers!
Spread the popcorn out to cool and then break into chunks, or form popcorn balls.