In large bowl, mix together beans, pineapple, molasses, BBQ sauce, mustard, 1/4 of the bacon, and 1/4 of the onions.
Add some salt and pepper, to taste.
Pour beans in 9- by 13-inch casserole dish and sprinkle remaining crushed onions and bacon on top. Cook in oven for 1 hour or until beans brown and bubble.