Preheat your oven to 350F and line a baking sheet with parchment paper or foil for easier cleanup. Lay the crackers in a single layer on the prepared baking sheet.
Cut each bacon slice into four smaller pieces that fit neatly over the crackers. Place one piece of bacon on top of each cracker.
Sprinkle a little brown sugar over each piece of bacon, then top with Parmesan cheese. Add black pepper and a tiny pinch of cayenne if using.
Bake at 350F for 13-15 minutes, or until the bacon is cooked through, the sugar has caramelized, and the crackers look crisp and golden.
Let the crackers rest for a few minutes after baking so the topping can set slightly. Garnish with parsley if desired and serve warm or at room temperature.