Preheat oven to 350˚
Cover pans with parchment paper. Toast walnuts in preheated oven for 5 minutes. Cool and chop. This an be done ahead of time and set aside.
Whisk all-purpose flour, wheat flour, salt, and baking soda.
Beat butter (room temperature), peanut butter, and sugars until light and fluffy. Add egg and vanilla. Beat until combined. Add banana and mix until combined.
Slowly add the flour mixture until dough is combined. Add walnuts, oats and chocolate chips.
Place on cookies sheet and be sure to press them down a bit. Cookies remain thick while cooking.
Bake for 12 minutes or until edges begin to brown. Do not overcook. Cool for five minutes and then remove from pan.