1.Slice your cheese into 8 (1/4-inch-thick by 11/2-inch-wide) slices. Cook your choice of bacon in a large high-sided skillet over medium heat, continue turning until crisp. Bring the bacon to a paper towel to drain. Reserve the skillet and 2 tablespoons bacon fat.
2. Bring your beef out onto a sheet of wax paper divide into 16 (3-ounce or generous 1/3 cup) piles. Press 1 pile into a 3 1/2-inch patty (using the cookie cutter as a guide) and top with some cheese, then put a second mound of beef on top, patting it onto other patty to enclose the cheese. Mold your Juicy Lucy Burger patty together to form a seal around the edges. Make 7 more burgers in the same fashion, then season the burgers generously with salt and pepper.
3. Heat the reserved bacon fat or oil in a large high-sided skillet over medium heat until hot. Cook the Juicy Lucy Burgers in 2 batches, covered, turning once, about 8 minutes for medium.
4. Place 2 burgers on the bottom portion of each bun and top with bacon, lettuce, tomato, onion, ketchup, and mustard, if desired. Serve.