In a 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 9x13 inch casserole dish and sprinkle remaining crushed onions and bacon on top. Cook in oven for 1 hour or until beans brown and bubbles. Serve warm.