I have found that every time I make cupcakes (or muffins, cornbread & hot dog muffins, etc) that the paper liner sticks to the finished cupcake. I know its not me because the Tim Hortons 'muffins' also stick to their liners.
How do I fix this?
Isn't that normal?
I suppose if it's causing a problem, you could use a non-stick (teflon, etc.) muffin pan, without the paper liners.
You could also try silicone-coated (parchment) liners. A quick check reveals that e.g., Amazon sells them.
<purist>cornbread shall be cooked in preheated cast iron, and if that's sticking, you need to season your cast iron properly.</purist>
One question would be why do you need the wrappers? If you don't need them at all, just grease the pans and don't use them.
I once agreed to make cupcakes for a wedding**, and as I knew this was a potential problem (and I didn't want people dressed nicely having to struggle with unwrapping frosted cupcakes), I greased the muffin tins, and purchased larger than normal wrappers. Once the cupcakes were baked, I removed them from the pan, and just placed them in the wrappers.
** I actually agreed to make a cake. I was told 'just a plain white cake'. So I took 3 months of cake decorating classes. Then somehow it changed to '150 cupcakes, with a rose on each one' ... luckily, I found a place where I could buy the roses, but I had to clean 'em out.
Have you tried the silicone baking cup liners? My wife and daughter used it whenever they bake muffins and banana bread and with perfect result, no burnt side and bottom and evenly cooked muffins non-sticky and easy to slide cupcakes and banana breads. You don't need to buy paper cupcake liners everytime because silicone cupcake liners are reusable and easy to clean. To learn more see... http://www.amazon.com/dp/B00P87R4PO
I stumbled upon Wilton parchment paper cupcake liners and voila!, no sticking to the paper. Something must be different though because cupcakes never used to stick to paper liners like they do now. The parchment works great though. Jo-Ann's sells them and you can find them in stores where Wilton products are sold.