While oven is heating, 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. HERE is an AWESOME video about oven baking bacon + tips!)
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.
When ready to make your grilled cheese, heat a large skillet over medium high heat.
Butter the outside of each slice of bread. Sprinkle each buttered side with a pinch of garlic powder.
Place each slice of bread onto the hot skillet, butter side down. Add one slice of cheddar and one slice of mozzarella to each slice of bread and allow to melt while bread toasts. Cook each slice of bread for approximately 2 minutes, or until the outside is fully toasted and browned to your liking.
Place two slices of bacon onto 4 pieces of the bread, side by side. Top with the remaining for slices of bread, 4 cheesy sandwiches. Sprinkle each hot sandwich with a little shredded cheddar (optional)
Cut each sandwich in half, between the bacon, to create 8 dippers.