Preheat the oven to 350 °F (180 °C). Line a large baking sheet with parchment paper. Set aside.
Place the mashed ripe banana in a mixing bowl. Make sure you measure ½ cup because not enough of it makes the cookie dry.
Add light olive oil, vanilla extract, and sugar. Whisk to combine.
Use a rubber spatula to stir in flour, and baking soda.
When the dough is consistent and thick, fold in the fresh blueberries, and chopped pecans. Stir gently to incorporate without breaking the blueberries too much.
Form 8 cookie dough balls of the same size and place them on the baking sheet leaving an inch apart.
Lightly oil your hand and press down the top of each cookie dough ball to form flatter cookies. These cookies expand a little in the oven.
Bake the cookies on the center rack for 16-20 minutes at 350 °F (180 °C) until the sides are nicely golden brown.
Let them cool down on the rack for 15 minutes before transferring to a cooling rack.
