Preheat oven to 350 degrees.
Chop the onion and cut the slices of bacon into pieces.
In a large pot over medium heat, fry the bacon 3-4 minutes.
Add the chopped onion to the bacon and cook 5-7 more minutes, stirring occasionally, until the onion is translucent and browned and the bacon is crisp.
Drain off most, but not all, of the bacon grease and add the can of beans to the bacon and onion.
Add the brown sugar and barbecue sauce and return beans just to a boil over medium heat.
Reduce the heat to low and simmer for 10-15 minutes, stirring every few minutes.
Place beans into a greased casserole dish and bake uncovered for 35-40 minutes, until bubbly.
Enjoy!