In large oven safe pot heat baked beans. Meanwhile take half the bacon and cut into bite size pieces. Cut off as much of the fat as possible. Cook bacon in pan until almost done. Remove bacon to separate plate, set aside. drain bacon grease from pan, reserve and set aside. Cut remaining bacon in half. Cook remaining bacon until almost done. Remove bacon and set aside on separate plate. Drain bacon grease from pan. Reserve and set aside.
Add 1 Tablespoon of reserved bacon grease to pan you cooked bacon in. Place chopped onion in the same pan and saute until onion is tender. Remove onions to plate with chopped bacon. Add about 2 tablespoon of the bacon grease to same pan, heat and add pineapple tidbits. Stir and heat through. Sprinkle in mollasses and mix through. Then sprinkle in half the plain bread crumbs and mix through. Heat through on low about 2 minutes. Mix in the chopped bacon and onions. Remove from heat.
Mix bacon and pineapple mixture into the baked beans. Mix in remaining half of bread crumbs. Mix in half the brown sugar. Keep beans in large pot or transfer to large baking dish. Lay strips of cooked bacon strips on top of beans and drizzle mollasses over top of bacon strips. sprinkle remaining half of brown sugar on top. Bake at 350 degrees for 30 minutes or until bacon is completely browned.