- Preheat the oven to 350°F (176°C) and line a baking sheet with parchment paper 
- In a medium bowl whisk the 1 cup oats, 1 cup flour, ¼ cup cacao powder, 1 teaspoon baking soda, 1 teaspoon baking powder, 1 teaspoon cinnamon, and ½ teaspoon salt until well combined. 
- In a large mixing bowl, beat the banana and ¾ cup sugar until smooth and creamy. 
- Add the 3 tablespoon coconut oil and 1 tablespoon vanilla and whip until light and creamy. 
- Slowly add the flour mixture and blend until just combined. 
- Stir in the 2 cups chocolate chips and ½ cup chopped walnuts until fully incorporated in the cookie dough and drop by tablespoons on the baking sheet. 
- Press one walnut in the center of each cookie (optional). Bake for 10 to 12 minutes and cool on a wire cooling rack. 
- Store in an airtight container for up to four days or freeze for up to two months.