PREHEAT oven to 400°. Sprinkle bacon with brown sugar and pepper; transfer to a wire rack set inside a foil-lined rimmed baking sheet and bake until browned and crisp, 20–25 minutes. Let cool.
WHISK eggs, milk, vanilla, cinnamon, and salt in a large baking dish. Dip bread slices into egg mnixture and let sit, turning to coat, until bread has absorbed most of the liquid, about 5 minutes.
MELT 1 Tbsp. butter in a large skillet over medium heat. Cook 2 slices of bread until golden brown, about 3 minutes per side. Repeat with remaining 1 Tbsp. butter and 2 slices of bread.
ASSEMBLE sandwiches using leftover cranberry sauce, Kretschmar Pan Roasted Turkey, arugula, and bacon, and cut into halves and serve.