In a large pot over medium heat, melt the butter. Add the chopped onions and garlic, and sauté for 10-20 minutes.

Add the rest of the sauce ingredients and mix well.

Let simmer for 15 minutes until the cheese is fully melted. Add the cooked spaghetti and mix well. Preheat oven to 375 degrees Fahrenheit.

Add the spaghetti mixture into a 9×13 greased baking dish. Top with American cheese slices. (Cover it really well, even put a double layer ).

Bake for 30 minutes, the cheese on top should be lightly golden.