Preheat oven to 375
Line two cookie sheets with parchment paper.
Mix pumpkin, peanut butter, and egg yolks until combined.
Add flour and baking soda to the wet mixture.
Mix on low until the dough is formed.
On a lightly floured surface, roll dough to 1/4 inch thick rectangle.
Using a pizza cutter or sharp knife, cut into squares or use your own cookie cutters.
Place treats on lined cookie sheets so they are not touching.
Bake for 20 minutes. Treats will be nicely browned on the bottom.
Turn off oven and open the door slightly. Allow treats to cool in the oven for an additional 20 minutes, or until they are crisp.
Cool completely before storing in an airtight jar or container.