Preheat oven to 350F. Line two baking sheets with parchment paper.
In a bowl, stir together all of the dry ingredients.
In the bowl of your electric mixer (or with a hand mixer), combine mashed banana, butter, white and brown sugars.
Add in egg, vanilla and lemon juice and beat to combine.
Slowly add the dry ingredients to the wet, mixing on low speed until just combined.
Stir in the chocolate chips and pecans.
Scoop cookies using medium cookie scoop (about 2 tbsp) on the baking sheets about 2 inches apart.
Bake for 10-12 minutes until set, but still slightly soft.
Let cool on the baking sheet for 5 minutes, then transfer to wire rack to cool completely.