Preheat the oven to 375 degrees F. Arrange the bacon on a wire rack set on a rimmed baking sheet. Bake until the fat starts rendering, about 10 minutes. Remove from the oven and blot the bacon with paper towels on both sides.
Combine the brown sugar, maple syrup and cayenne in a small microwave-safe bowl. Microwave, stirring, until smooth, 30 seconds to 1 minute. Brush the bacon with half the syrup mixture and sprinkle with half the ground peppercorns. Bake until the bacon browns around the edges, about 15 minutes. Flip and blot the other side with paper towels, then brush with the remaining syrup mixture (reheat in the microwave, if necessary); sprinkle with the remaining peppercorns. Continue baking until the bacon browns and the sugar melts, 15 to 20 more minutes. Let cool slightly.