Mix together your whiskey with 1 cup brown sugar and cayenne pepper in a small saucepan over medium/high heat. Stir to combine. Bring to a boil and then reduce to a simmer for 10 minutes. Remove from heat and set aside.
Place each strip of bacon directly on a baking sheet, allowing a bit of space between strips. Brush the bacon with the whiskey reduction and then sprinkle with remaining 1/4 cup brown sugar.
Place bacon in the oven and cook for 20 minutes, checking after 12 minutes. Ovens vary, so you want to make sure they don't burn. Mine took the full 20 minutes.
Take bacon out of the oven and allow to sit on a paper towel to cool/drain.