Preheat your oven to 350°F (175°C).
In a large bowl, combine rolled oats and almond flour.
In another bowl, mix honey, peanut butter, and mashed banana until smooth.
Add vanilla extract and baking powder to the wet mixture.
Pour the wet ingredients into the dry mixture and stir until combined.
Fold in chocolate chips and nuts if using.
Scoop tablespoon-sized portions onto a lined baking sheet.
Flatten each cookie slightly with the back of a spoon.
Bake for 12-15 minutes or until golden brown.
Let cookies cool on a wire rack before serving.