In a large bowl, whisk the egg, pumpkin purée, and oil together until well combined.
Add in the cornbread and cinnamon. Mix until no more flour is showing.
Divide the batter equally into the muffin tin. Each should be about 3/4 full. Bake for 25 min or until a toothpick inserted in the center of the muffin comes out clean. Enjoy!
Notes
1 cup of pumpkin purée is about half a standard can