In a medium saucepan, combine the brown sugar, honey whiskey, soy sauce, ketchup, honey, apple cider vinegar, Sriracha, liquid smoke, minced garlic, instant coffee, onion powder, paprika and cayenne. Whisk together with a wire whisk.
Heat over medium high heat until boiling, then boil for 2 minutes.
Reduce the heat to medium low and allow to simmer for 10 minutes, stirring occasionally.
Whisk together the cornstarch and water until a thick slurry forms and pour that into the sauce, whisking for another minute or two until the mixture has thickened up to the desired consistency you want for the BBQ sauce.
Remove from the heat and allow to cool.
Transfer to a mason jar or airtight container.
Notes
Sauce will keep in the fridge for 1 month. Replace Sriracha with hot sauce or omit entirely. Cayenne can also be omitted if you don't like heat. Liquid Smoke and instant coffee provide a smoky flavor to the sauce, but both can be omitted or the liquid smoke can be replaced with Worcestershire sauce. Alcohol does evaporate somewhat when cooking. If you are concerned about the content, you can replace the whiskey with water, although the recipe will not be the same.