1. Preheat CRUX Panini Maker and grease grate well.
2. Stir together mayonnaise and chipotle; spread over 8 slices of bread. Top 4 slices of bread with 1 slice cheese each; divide chicken over top and sprinkle with salt. Layer avocado and tomato over top.
3. Top remaining 4 slices of mayonnaise-chipotle bread with bacon, spinach, red onion, alfalfa sprouts and remaining cheese; stack over tomato slices. Cap sandwiches with remaining bread.
4. In batches, wearing oven mitts, place sandwiches on CRUX panini grill. Lower top grill, making sure it lies evenly on sandwich. Use handle to press down lightly several times during grilling time; cook for 5 to 7 minutes or until bread is toasted and cheese starts to melt. Cut each sandwich in half and secure with toothpicks.