Preheat oven to 350°F. Coat a 13- x 9-inch baking dish with cooking spray; set aside. Stir together ketchup, brown sugar, Dijon mustard, molasses, and Worcestershire sauce in a large bowl until combined. Stir in cannellini beans, baked beans, and pork.
Cook sausage in a large skillet over medium-high, stirring often, until lightly browned, about 3 minutes. Stir in onions and cook, stirring often, until softened, about 2 minutes. Remove from heat, add paprika and cumin, and stir constantly until fragrant, about 30 seconds. Transfer to bean mixture; add vinegar and stir to combine.
Transfer bean mixture to prepared baking dish. Bake in preheated oven until bubbly, 55 minutes to 1 hour. Let stand 10 minutes before serving.
