Place brisket, fat side up, in a shallow 2 1/2-quart casserole. Combine remaining ingredients except Barbecue Sauce, mixing well. Pour mixture over brisket; cover and refrigerate overnight.
Place casserole in oven. Cover and bake at 250° for 5 hours.
Remove brisket from casserole; discard marinade. Cut brisket diagonally across the grain into thin slices.
Return sliced brisket to casserole; pour Barbecue Sauce over top. Bake, uncovered, at 300° for 30 minutes. Remove brisket to serving platter, and serve with Barbecue Sauce.