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

In a medium bowl, stir together oat flour, rolled oats, and ground flaxseed.

In another bowl, whisk together pumpkin puree, egg, and peanut butter until smooth.

Pour the wet mixture into the dry ingredients and stir until a stiff dough forms.

Add water, 1 tablespoon at a time, only if needed to help the dough come together.

Lightly flour a work surface with oat flour and roll the dough to 1/4 inch thickness.

Cut out shapes with small cookie cutters and place them on the prepared baking sheet.

Bake for 20–25 minutes, until the treats are dry and lightly browned around the edges.

Turn off the oven, leave the treats inside, and let them sit for 10–15 minutes to dry further.

Transfer the treats to a wire rack and cool completely before serving or packaging.