Cook the bacon in a skillet over medium heat until crispy but not overdone, about 8 to 10 minutes. Transfer to a paper-towel-lined plate to drain. Tear each slice in half to create 8 strips. Keep warm.

Spread softened butter on both sides of each bread slice. Toast in the skillet over medium heat for 2 to 3 minutes per side until lightly golden. Do not over-toast. Set aside.

Wash and dry the lettuce. Slice the tomato into 3/8-inch rounds and place on a paper-towel-lined plate for a few minutes to absorb excess moisture.

Slice the avocado half into thin strips and set aside.

Spread about 1 1/2 tablespoons of mayonnaise onto one slice of toasted bread. Layer on the lettuce, then 2 tomato slices. Season the tomatoes with salt and pepper.

Lay all 8 bacon strips evenly over the tomatoes. Layer the avocado strips on top. Add a final pinch of salt and pepper if desired.

Spread the remaining 1 1/2 tablespoons of mayonnaise on the second bread slice. Press gently on top, slice in half with a serrated knife, and serve immediately.