Preheat the oven to 350°F. Line a baking sheet with parchment paper.

Place 1 ¼ cup oats in a blender jar and process until the oats form a fine powder. 

In a large mixing bowl, combine the pumpkin, brown sugar, and egg. Whisk until smooth. 

Add the oat flour, baking powder, and salt to the pumpkin mixture, and stir to combine. 

Add the remaining ½ cup oats and chopped pecans to the cookie dough and fold to distribute evenly. 

Drop 2 tablespoon-sized mounds of cookie dough onto the prepared baking sheet. 

Using your hands or the back of the spoon, flatten and spread each mound of dough into the shape of a cookie.

Place the baking sheet in the preheated oven and bake for 13 to 15 minutes.

Remove from oven and allow cookies to cool down for 5 minutes before serving.