Chocolate Chip Banana Cookies

Step 1
Preheat oven to 350 degrees F (175 degrees C). Line baking sheets with parchment paper.

Step 2
Spread walnuts onto a baking sheet.

Step 3
Bake in the preheated oven until walnuts are toasted and fragrant, 5 to 7 minutes. Remove from oven and cool; coarsely chop.

Step 4
Whisk all-purpose flour, whole wheat flour, salt, and baking soda together in a bowl. Beat butter, brown sugar, and white sugar together in a bowl using an electric mixer until pale and fluffy; add egg and vanilla extract. Beat until just combined. Beat banana into creamed butter mixture until just combined.

Step 5
Stir flour mixture into creamed butter mixture until dough is just combined; fold in oats, chocolate chips, and walnuts. Drop heaping spoonfuls of dough onto the prepared baking sheets, spacing each mound about 1 1/2 inch apart.

Step 6
Bake on the center rack of the preheated oven for 6 minutes. Rotate pans and bake until edges are browned, 6 to 7 more minutes. Cool cookies on the baking sheets for 5 minutes before transferring to wire racks to cool completely.