Preheat oven to 400 degrees. Drain can of pineapple rings and save syrup. For each pound of baked beans, stir in 2 tablespoons brown sugar, 1 tablespoon syrup from the pineapple slices, 1 tablespoon catsup and 1 teaspoon mustard.

Bake in shallow casserole dish for 30 minutes. Then top with drained pineapple slices and bake for another 30 minutes.