Tiffany's Baked Beans

1 (3 pound) can pork and beans (I use Van de Kamp)
2 tablespoons dark molasses
3 tablespoons brown sugar (add more if you like it sweeter)
1/2 cup ketchup
1 medium red onion, chopped

Combine all ingredients and place in a baking dish. Bake 350 degrees F for 40-60 minutes. Can be made on the stove also.