Prepare bacon according to package directions; drain and set aside.
Sprinkle tomato slices evenly with salt and pepper.
Spread 1/2 tablespoon dressing on 1 side of each bread slice. Top each dressing-coated side of 4 bread slices with 1 provolone slice; top each remaining 4 bread slices with 1 Cheddar slice. Top each provolone slice with 2 tomato slices, 2 bacon slices, and 2 avocado slices.
Cook bread slices, cheese side up, on a hot nonstick electric griddle at 325° or in a hot nonstick skillet coated with cooking spray over medium heat 4 to 7 minutes or until browned.
Press together Cheddar cheese-topped bread slices and provolone-topped bread slices. Cut in half diagonally, and serve immediately.