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

In a medium bowl, whisk together the flour and cinnamon, if using.

In a separate bowl, stir together the pumpkin puree, peanut butter, and water or broth until smooth.

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

If the dough is too dry, add water 1 teaspoon at a time; if it is too sticky, add a little more flour until it is soft and workable.

Lightly flour a clean work surface and roll the dough out to about 1/4 inch thickness.

Cut the dough into small wafers using a knife, pizza cutter, or small cookie cutters, and place them on the prepared baking sheet slightly apart.

Bake for 20 to 25 minutes, until the wafers are firm and the edges are lightly golden.

Turn off the oven and let the wafers sit inside for 10 to 15 minutes for extra crunch, then remove and cool completely on a wire rack.

Once fully cooled, store the wafers in an airtight container until ready to serve to your dog.