Adapted from marthastewart.com
1/2 cup whole-wheat flour
1 teaspoon coarse salt
1/2 teaspoon baking soda
3/4 cup (1 1/2 sticks) unsalted butter, softened
1/2 cup granulated sugar
1/2 cup packed light-brown sugar
1 large egg
1 1/2 teaspoons pure vanilla extract
1/2 cup mashed ripe banana (about 1 large)
1 cup old-fashioned rolled oats
8 ounces semisweet chocolate, coarsely chopped into 1/4-inch chunks*
1/2 cup coarsely chopped walnuts (about 2 ounces), toasted
1.Preheat oven to 375 degrees. Whisk together flours, salt, and baking soda in a small bowl; set aside.
2.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.
3.Add flour mixture; mix until just combined. Stir in oats, chocolate chunks, and walnuts.
4.Using a 1 1/2-inch ice cream scoop, drop dough onto baking sheets lined with parchment paper, spacing about 2 inches apart.
5.Bake cookies, rotating sheets halfway through, until golden brown and just set, 12 to 13 minutes. Let cool on sheets on wire racks 5 minutes. Transfer cookies to wire racks; let cool completely (if you can resist!)