Healthy Banana Bread Granola Bars

very ripe banana, mashed 1/4 cup unsweetened applesauce 2 tbsp honey 1 egg white 1 tsp cinnamon 1/2 tsp vanilla extract 1/2 tsp salt 3 tbsp + 1 tsp brown sugar 2 cups rolled oats 2 tbsp flax seeds 1 tsp chia seeds