Preheat the oven to 350 degrees Fahrenheit.
In a large pan, add 2 tbsp olive oil until warm. Then add the 1/2 chopped onion into the pan and saute for a few minutes until the onions turn translucent.
Add 1/2 lb ground sausage into the pan and cook, breaking up the sausage with your spoon until cooked through.
In a 9x13 pan (I used aluminum), add 28 oz baked beans, 10 oz apple pie filling, cooked sausage and onions, 2 tbsp mustard, 1 tbsp worcestershire sauce, 3 tbsp brown sugar, 1 tbsp barbecue rub seasoning, and 1/4 cup barbecue sauce. Mix to fully combine everything.
Put this pan in the oven and bake for 45 minutes until warmed through and bubbly on the edges.
Serve with cooked barbecue meat and enjoy!