1/3 cup of baking soda
spray bottle of water
Take baking soda and sprinkle it over the bottom of the oven wherever your spills are. Then take the spray bottle full of water and spray all over the baking soda. Now you can either let it sit for a few hour or for harder/tougher stains let it sit overnight. Once it has sat for a bit you can take a soft scraper or sponge and wipe away the mess.