Directions

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large mixing bowl, cream together the softened butter and brown sugar until light and fluffy.
Add the mashed bananas and vanilla extract to the butter mixture, and mix until well combined.
In a separate bowl, whisk together the rolled oats, flour, baking soda, cinnamon, and salt.
Gradually add the dry ingredients to the wet ingredients, stirring until just combined.
Fold in the chopped walnuts and raisins or chocolate chips, if using.
Drop tablespoon-sized portions of the dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 12-15 minutes, or until the edges are golden brown.
Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.

Variations & Tips
For a gluten-free version, substitute the all-purpose flour with a gluten-free flour blend. You can also experiment with different mix-ins such as dried cranberries, sunflower seeds, or shredded coconut for added texture and flavor. If you prefer a sweeter cookie, increase the brown sugar to 3/4 cup. To make the cookies vegan, replace the butter with coconut oil or a plant-based butter substitute.