Preheat the oven to 180°C (350°F). Prepare a baking sheet lined with parchment paper.

In a large bowl, mix the oats, flour, sugar substitute, baking powder, and salt.

In a separate bowl, whisk the coconut butter, egg, and vanilla extract.

Add the wet ingredients to the dry ingredients and mix well until combined.

Add the nuts to the mixture and fold gently.

Shape the cookie dough into small balls and place them on the baking sheet, leaving space between each one.

Bake the cookies for 10-12 minutes, or until golden brown.

Let the cookies cool on the baking sheet for a few minutes before transferring them to a cooling rack to cool completely.

Store the cookies in an airtight container until serving to keep them crisp.