If the cornbread is not cooking thoroughly it’s a sure sign the batter isn’t cooking long enough. If the bottom is thick, greasy and soggy it’s because the baking dish WAS NOT preheated before adding the batter. The next time you bake cornbread, try the following:
Preheat oven to 425 degrees. Grease baking dish (or skillet). Preheat until the oil is sizzling hot. With an oven mitt, carefully remove baking dish from oven. Pour in batter. Bake about 20 to 25 minutes until a knife inserted in center comes out clean. This means it’s throughly cooked. Kindly let me know if this helps.