1 c. all purpose flour
1/2 c. whole wheat flour
1 tsp. course salt
1/2 tsp. baking soda
3/4 c. (1 1/2 sticks) unsalted butter, at room temperature
1/2 c. granulated sugar
1/2 c. packed light brown sugar
1 large egg
1 1/2 tsp. pure vanilla extract
1/2 c. mashed ripe banana (about 1 large)
1 c. old fashioned rolled oats
8 oz. semisweet chocolate coarsely chopped into 1/4-inch chunks
1/2 c. coarsely chopped walnuts (about 2 oz.), toasted
Prep. Time: 40 min.
Bake Time: 13 min. per batch
Makes about 36
To toast nuts, spread in a single layer on a rimmed baking sheet, and bake in a 350º oven for about 10 minutes.
To make cookies, preheat oven to 375º. Whisk together both flours, salt, and baking soda in a bowl. Put butters and both sugars into separate bowl and mix on medium speed until pale and fluffy. Reduce speed to low. Add egg and vanilla; mix until combined. Reduce speed to low. Mix in banana. Add flour mixture; mix until just combined. Stir in oats, chocolate chunks, and walnuts.
Using a 1 1/2 inch ice cream scoop, drop dough onto baking sheets lined with parchment paper, spacing about 2 inches apart. Bake cookies, rotating sheets about half way through, until golden brown and just set, 12-13 minutes. Let cool on sheets on wire racks for 5 minutes. Transfer cookies to wire racks; let cool completely.
Cookies can be stored in airtight containers at room temperature up to 2 days or frozen.