Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large bowl, combine rolled oats, whole wheat flour, baking powder, cinnamon, and salt.

In another bowl, mix together the mashed banana, honey, and melted coconut oil until smooth.

Pour the wet ingredients into the dry ingredients and stir until just combined.

Fold in the raisins and nuts, if using.

Using a tablespoon, scoop the dough onto the prepared baking sheet, spacing them about 2 inches apart.

Flatten each cookie slightly with the back of the spoon.

Bake in the preheated oven for 12-15 minutes, or until the edges are golden brown.

Remove from the oven and let cool on the baking sheet for 5 minutes.

Transfer to a wire rack to cool completely.