Ready in 1 hour
If you like banana bread and chocolate chip cookies, then you will love this cookie. The cookie has a soft texture, almost like a thin muffin top. If you prefer a crispier cookie, make smaller cookies (one tablespoon of dough).
Preheat oven to 375 degrees.
Whisk together flours, salt, and baking soda in a small bowl; set aside.
Put butter and sugars into the bowl and mix with an electric mixer; mix on medium speed until pale and fluffy. Reduce speed to low. Add egg and vanilla; mix until combined. Mix in banana. Add flour mixture; mix until just combined. Stir in chocolate and walnuts.
Refrigerate dough for 15 minutes.
Drop dough onto baking sheets lined with parchment paper, spacing about 2 inches apart. Bake cookies until golden brown (about 12 minutes).
Transfer cookies to wire racks; let cool completely.