This Missouri-style sauce is inspired by B.B.’s Lawnside in Kansas City. Apple juice makes it sweet and ground cloves and cinnamon make it spicy—think of it as a sort of liquid apple pie.
Step 1: Place the ketchup, apple juice, molasses, cider vinegar, brown sugar, granulated sugar, red pepper, cinnamon, cloves, and celery seed in a large heavy nonreactive saucepan and gradually bring to a boil over medium heat, whisking to mix.
Step 2: Reduce the heat to low and let the sauce simmer until thick and richly flavored, about 40 minutes, whisking it often. When it’s properly cooked down, you’ll have about 2-1/2 cups. Season the sauce with salt and black pepper to taste; it should be highly seasoned. The sauce can be refrigerated, covered, for several weeks. Let it return to room temperature before using.