Preheat oven to 325 degrees F. Line 2 baking sheets with parchment paper. Set aside.
In a large bowl, combine pumpkin, peanut butter, broth/milk, and egg. Mix well.
Add 2 cups of flour and baking powder and, using a rubber spatula, mix until combined. Stir in oats.
Continue to add flour 1/4 cup at a time until dough is no longer sticky, kneading on a floured table top if necessary to incorporate flour.
Turn dough on to a table and use a rolling pin to roll dough to 1/4-inch thickness. Use cookie cutters to create shaped cookies or a pizza cutter to create squares or logs. Re-roll scraps until all of the dough has been used.
Place cookies on prepared baking sheets. Bake for 8-12 minutes (depending on size,) then use a spatula to flip cookies. Bake for an additional 7-13 minutes, adding more time for crunchier cookies.
Remove from oven. Cool the cookies completely before treating your dog!