If you put sugar in cornbread, it ain't cornbread, it's cake!
When I want Mexican cornbread (goes great with chili)
Whole Kernal Corn
and cook it in my Griswald cast iron skillet.
If you wipe it with oil or use one of the cooking sprays, they should come right out. I have found that cornbread comes out better if the pan / tin is hot when you pour the batter into it.