Cook the bacon with your preferred method*, until crispy. Pat them dry with a paper towel to absorb any excess grease.
Make the sandwich:
Spread a thin layer of peanut butter on both slices of bread. Place the banana slices on one of the bread slices, and top with bacon pieces or crumbled, close the sandwich.
Note, use toasted bread for the classic Elvis sandwich, or enjoy it on soft sandwich bread.
Pack it for later:
If making this sandwich for later, pack it inside a compartment of a lunchbox. In another compartment or container, store fruit, veggies, and your favorite sides. Add an ice pack in the lunch bag if necessary.