Place 2 baking sheets on the countertop, then lay aluminum foil over the sheets.
Spray the aluminum foil with nonstick spray.
Open the packages of bacon and then lay the bacon pieces on the sheet in a single layer.
Place the baking sheets into the preheated oven and cook until the bacon is slightly crispy, around 25-30 minutes. Just make sure to watch it so the bacon doesn't burn!
When done, remove the baking sheets from the oven.
Place 2-4 sheets of paper towel on a plate, then remove the bacon and lay it on the paper towel sheets. This will allow the grease to soak into the towels and get off the bacon.
In a sink colander, rinse the tomatoes and lettuce.
On a cutting board, slice the tomatoes and then set them on a plate.
Place pieces of lettuce on a plate.
If desired, toast the bread before assembling the BLT.
Spread mayonnaise on the bread, then layer bacon pieces, lettuce and tomato slices.
Top the BLT sandwich with an additional piece of bread and then enjoy!