In a large skillet, cook the bacon over medium heat until crisp, about 7 minutes; transfer to a paper towel to drain.
In a medium bowl, mix together the eggs and mayonnaise; season with salt and pepper.
Spread the egg salad on each of 8 slices of toast and divide the bacon among 4 of them. Stack the egg-only toasts on top of the bacon-topped toasts. Top with the lettuce and tomato; season with salt and pepper. Place the 4 remaining toasts on top. Halve the sandwiches.
