01 -
Heat your oven to 300°F and spray an 8-inch square baking pan with cooking spray.
02 -
In a medium bowl, whisk together the oats, flour, baking powder, cinnamon, and salt until well combined.
03 -
In another bowl, whisk the egg white and vanilla. Add the peanut butter and stir until smooth. Pour in the maple syrup and mix thoroughly. Finally, stir in the milk until everything is well combined.
04 -
Add the dry oat mixture to the wet ingredients and stir just until combined - don't overmix!
05 -
Spread the batter evenly in your prepared pan. Bake at 300°F for 10-12 minutes until the edges feel firm but the center still looks slightly underdone.
06 -
Let the bars cool completely to room temperature in the pan. For the best soft and chewy texture, allow them to rest for at least 4 more hours before cutting into squares.