Cook bacon in a large skillet over medium heat (or bake in the oven, if you prefer!) until crisp. Remove to a paper towel-lined plate to drain grease.
In a shallow dish, combine the eggs, milk, sugar, and cinnamon. Whisk with a fork until well combined.
Spread about 1 tablespoon of peanut butter on each of the 8 slices of bread. Top 4 of the slices with a layer of banana slices, followed by 3 of the bacon slices. Top with the remaining 4 slices of bread.
Melt 1 tablespoon of butter in a skillet over medium heat, dip your stuffed French toast into the egg mixture - dip both sides - and place in the skillet. Do this in batches if necessary, adding more butter for each batch if needed. Cook each side until browned and crisp before turning and repeating on the other side. This can take 3-5 minutes per side, depending on your burner's temperature. Low and slow is better than fast and burnt.
Remove to a plate and drizzle with maple syrup and sprinkle with powdered sugar (I used a sifter to sprinkle it on). Top with extra banana slices, if you like!