Blueberry Barbecue Sauce

Combine blueberries, ketchup, vinegar, brown sugar, molasses, chili powder and black pepper in medium saucepanStir in ½ cup waterBring the mixture to a boil over high heat, stirring constantlyReduce heat to low and simmer, stirring occasionally until sauce is slightly thickened and chunkyCool to room temperature then refrigerate until ready to useIn a bowl or glass baking dish, coat the tenderloins with 2 ⁄ 3 cup of the sauceCover and refrigerate 1 to 4 hoursWhen ready to cook, preheat the oven to 400°FPlace the tenderloins in a roasting panDiscard any marinade left in the bowlRoast 15 minutesTurn the tenderloins and spoon on ¼ cup of the remaining barbecue sauceRoast 12 to 15 minutes longer to an internal temperature of 160°FRemove to a platter, cover loosely with aluminum foil and set aside 5 minutes until the temperature rises to 165°FSlice ½-inch thick and serve with additional barbecue sauce, if desired