Parent prep: Preheat the oven to 350 degrees Fahrenheit and line an 8″ x 5″ pan with parchment paper.
Kids’ turn: Combine bananas, oats, eggs, maple syrup, baking soda, vanilla and salt in a blender. Blend until you have a smooth batter (about one minute). Fold walnuts into mixture (Parents: make sure to monitor this step!).
Parents: Pour batter into prepared pan, arrange banana slices on top and bake about 20 minutes (or until a toothpick comes out clean). Let cool in pan for 15 minutes.