The Recipe for these little gems is:
2 cups of ap flour
1 cup whole-wheat flour
2 teaspoons salt
1 tsp baking soda
3 sticks unsalted butter, softened
1 cup sugar
1 cup light-brown sugar
1 tbsp vanilla
1 cup mashed banana (about 2 large)
2 cup rolled oats
16 oz semisweet chips or chunks
1 cup chopped walnuts
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 of an electric mixer fitted with the paddle attachment; 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 oats, chocolate chips and walnuts.
Drop dough onto baking sheets lined with parchment paper, spacing about 2 inches apart. Bake cookies, rotating sheets halfway through, until golden brown and just set, 15 minutes. Let cool on sheets on wire racks 5 minutes. Transfer cookies to wire racks; let cool completely. Cookies can be frozen in freezer bags for up to about 1 month.