Wash hands with soap and water.
Preheat oven to 350 degrees.
Line a baking sheet with aluminum foil. Make sure the baking sheet has short sides to keep the bacon grease in the pan.
Cut the bacon slices in half and lay them in a single layer on the baking sheet.
Wash hands with soap and water after handling raw bacon.
Cook bacon in the oven for 12 to 15 minutes until crispy.
While the bacon cooks, cut the ciabatta rolls in half and spray with cooking spray.
On a grill pan over medium heat, toast the ciabatta rolls and then set aside.
If using fresh pineapple, scrub with a clean vegetable brush under running water before cutting into it. Remove the outer skin and slice into rounds.
Sprinkle the pineapple with a pinch of black pepper and add to the grill pan. Cook over medium heat until grill marks appear and the pineapple is tender. Time will vary if the pineapple is fresh or canned.
Gently rub the lettuce leaves under cold running water. Set aside on a clean towel to dry.
Line a plate with a paper towel. Once the bacon slices are cooked, remove them from the oven, place them on the towel-lined plate, and set them aside.
In a small bowl, mix ¼ cup barbecue sauce and 2 Tablespoons of pineapple marmalade until well combined. Spread equally inside the top and bottom of grilled ciabatta rolls.
Build the sandwiches by placing a slice of pineapple on the bottom of each roll. Then top each pineapple with six pieces of bacon. Top the bacon with a lettuce leaf, and then add the ciabatta top.
Repeat until all four sandwiches are done.