The papers came off!
What we didn't eat the first day got wrapped in cellophane and left on the kitchen table. The next morning when my husband went to eat one for breakfast he showed me that the paper came right off. The muffin was a bit soggy and so was the paper, but on the plate was the paper and only the paper with not one crumb of muffin stuck to it. He immediately took the papers off the remaining 3 muffins and rewrapped them.
It was a busy day and neither of us felt like a snack that evening and forgot about the muffins until the next morning.
My husband took the wrap off the plate and Whoa! We should have refrigerated these things, because the fruit in the muffins fermented and it smelled like wine-infused muffins under that wrap! He spent a good 3 minutes debating whether or not to still eat them before tossing them out.
So now two things to remember the next time I make them:
Don't use cupcake papers
Refrigerate or freeze them at the end of the day they're made