Cook the bacon in a skillet over medium heat until crisp.

Transfer the bacon to a paper-towel-lined plate and allow it to cool slightly.

Chop the bacon into bite-sized pieces.

Finely chop the romaine, dice the tomatoes, and dice the avocado.

In a small bowl, combine the mayonnaise, lemon juice, garlic powder, and black pepper.

In a large bowl, gently combine the lettuce, tomatoes, avocado, and chopped bacon.

Add a small amount of the mayo mixture and toss lightly.

Slice and toast the bagels until lightly golden.

Spread the remaining mayo mixture over the cut sides of the toasted bagels.

Divide the chopped BLT filling evenly between the bottom halves of the bagels.

Top with the remaining bagel halves.

Slice and serve immediately.