Here is one we stole from "America's Test Kitchen". My other half likes it, I don't? But :
SWEET & STICKY K.C. BBQ SAUCE
1 Onion, minced & sweated ½ C Catsup
4 C Chix Broth ½ C Tomato Paste
½ C Molasses 1 TBS? Hot Sauce
1 C Dark Corn Syrup 1 tsp? Garlic Powder
1 C Apple Cider Vinegar 1 C Root Beer
2 TBS Brown Mustard
Simmer 1 to 1 ½ hour
The question marks are places I would make changes, but then it wouldn't be so sweet any more?
And another sweet sauce recipe from another source, not tested by me:
Kansas City-Style Barbecue Sauce, makes 3 cups
2 cups ketchup
1 cup water
1/2 cup cider vinegar
1/2 onion, finely sliced from root to tip (see Notes)
8 tbsp brown sugar
2 tbsp white sugar
1 1/2 tbsp freshly squeezed lemon juice
1 tbsp Worcestershire sauce
1/2 tbsp freshly ground black pepper
1/2 tbsp ground mustard
Good luck and good smoking.