Instructions

  1. Preheat oven to 350F; spray a 13x9 pan with cooking spray.
  2. Combine the flour, oats, baking powder and salt in a medium bowl; set aside.
  3. Beat the butter and sugars in a large bowl with an electric mixer at high speed until fluffy.
  4. Add eggs 1 at a time, beating well after each addition.
  5. Beat in the bananas and vanilla.
  6. Gradually add the flour mixture, beating a low speed just until combined.
  7. Stir in the chocolate chunks and walnuts by hand; spread evenly in the prepared pan.
  8. Bake for 45 minutes or until a wooden pick inserted into the center comes out clean.
  9. Cool completely in the pan on a wire rack.
  10. Cut into 24 bars.