In a small bowl, stir together the peanut butter, chia seeds and honey. Spread about 2 tablespoons of the peanut butter mixture over one side of 4 slices of bread. Top the peanut butter layer with a layer of sliced bananas. Sprinkle with cinnamon and flaked sea salt. Sandwich each with a second slice of bread. Cut in half diagonally and eat immediately or wrap for lunchboxes.