Combine onion, garlic, and Jack Daniel's Whiskey in a 3-quart saucepan. Saute' until onion and garlic are translucent, approximately 10 minutes. Remove from heat and light mixture; flame for 20 seconds. Add all remaining ingredients. Bring to a boil, then turn down to a medium simmer. Simmer 20 minutes, stirring constantly. Run sauce through a medium strainer to remove onion and garlic bits if you prefer a smoother sauce. Cool and enjoy.
NOTE: This sauce gets better with age. If time permits, keep it in the refrigerator a day or so to develop a deeper, richer taste.
Recipe by Ultimate BBQ Sauce Recipes! at http://www.bbq-sauce-recipes.com/citrus-based-sauces/69/pineapple-jack-daniels-bbq-sauce/