Preheat oven to 350°.
Grease a 2 1/2- to 3-qt. baking dish.
In a large skillet over medium heat, cook bacon until beginning to brown but still limp.
Stir in onion and cook until onion is soft and translucent and bacon is crisp, about 5 minutes more.
Spoon mixture into prepared baking dish.
Add baked beans, chili sauce, Worcestershire, mustard, paprika, and cumin.
Stir, taste to check seasonings, and add salt if you like.
Bake beans, uncovered, until bubbly throughout with a bit of browned crust around the edges of dish, about 45 minutes.
Serve hot.