In a mixing bowl, whisk together flour, oats, baking powder, salt and cinnamon for about a minute and set aside. In another bowl, mash bananas together with lemon juice. Blend banana, softened cannabutter and brown sugar until the mixture is smooth. Mix in the egg and vanilla extract.
Slowly add in dry ingredients and mix until combined. Stir in the pecans or walnuts and dark chocolate chips.
Chill the dough in the refrigerator for about 30 minutes. When you have about 15 minutes left, preheat the oven to 325 degrees. (This way, the oven will be ready to go when you remove the dough from the refrigerator. You don’t want the dough to sit at room temperature for too long.)
Scoop 1½-inch balls of dough and drop onto a non-stick baking sheet about 2 inches apart. Bake for 12-13 minutes. Remove when slightly soft to the touch.
Cool on baking sheet for at least 10 minutes, then transfer to a wire rack to cool completely. Makes 14 cookies.