Cut an approximately ½ inch off of the top of the garlic. Cut the roots so that the garlic will sit flat into a baking dish.
Remove some of the skin from the garlic but leave enough so that the cloves stay together. Place the garlic into a small baking dish and drizzle the olive oil over it.
Cover with foil. Place into the oven and bake at 325 degrees F. for 1 hour. Remove the garlic and let it cool until it can be handled.
In a medium saucepan combine water, pineapple juice, teriyaki sauce, soy sauce, and brown sugar. Bring the mixture to medium-high heat.
Stir occasionally until the mixture boils and reduce heat until simmering.
Squeeze the sides of the head of garlic until the pasty roasted garlic is squeezed out. Measure 2 teaspoons into the saucepan and whisk to combine.
Add lemon juice, white onion, Jack Daniels, crushed pineapple and cayenne pepper and stir.
Let the mixture simmer for 40-50 minutes or until the sauce has been reduced by about ½ and is thick and syrupy.