Spray a casserole pan with non-stick spray. Set aside.
Pour the chili into the casserole dish. Spread out evenly.
Toss the mozzarella cheese on top of the chili.
In a medium size bowl combine the cornbread muffin mix with 1/2 cup milk. Stir well. Pour over top of the casserole. You don't have to be overly careful. It will seem like it's not enough liquid but trust me, it fluffs right up so have faith. Spread the mixture out a bit.
Place the casserole dish in the preheated oven and cook for 15 to 20 minutes, or until the top turns golden brown.