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

In a large mixing bowl, whisk together the pumpkin, eggs, and peanut butter until smooth and well combined.

Stir in 2½ cups of oat flour and the cinnamon (if using) until a soft dough begins to form.

Gradually add more flour—1 tablespoon at a time—until the dough is no longer sticky and easy to roll.

Lightly flour your surface and roll the dough out to 1/4 to 1/2 inch thickness. Cut into shapes with cookie cutters.

Place treats on the prepared baking sheet and bake for 20–22 minutes, or until crisp and lightly golden.

Let the treats cool completely before serving or storing. They will firm up as they cool.