Adjust oven racks to upper-middle and lower-middle positions and heat oven to 350 degrees. Line 2 rimmed baking sheets with aluminum foil. Cut bacon in half crosswise. Arrange bacon on prepared sheets.

Combine sugar, rosemary, and pepper in a bowl. Sprinkle sugar mixture evenly over bacon (do not flip and sprinkle on second side). Use your fingers to spread sugar mixture evenly over each piece.

Bake until bacon is dark brown and sugar is bubbling, 20 to 25 minutes, switching and rotating sheets halfway through baking (if bacon on 1 sheet finishes cooking sooner, it’s OK to remove this sheet from oven first). Transfer bacon to a wire rack and let cool for 5 minutes. Serve.