I love cornbread muffins and always make a double batch for the freezer. I always let them thaw on the countertop for an hour before reheating. I had been zapping them in the microwave for about 15 seconds.
I recently discovered cornbread muffins taste better if you reheat them in the oven at 375 for about 8 minutes. Gives a really nice crispy/crunchy texture to the outside of the muffin. Once in awhile the bottom will scorch a little where it sits on the cookie sheet. No big deal. Break that piece off and toss it in the bin.
What else reheats better in an oven?