Pre-heat oven to 350 degrees. Line 2 cookie sheets with parchment or grease them. If using a stand mixer, fit with paddle attachment. (I typically mix these by hand but a mixer works great too).
Stir together pumpkin, carrots, and peanut butter.
Mix in flour. Dough will be stiff.
Turn out onto floured work surface. Roll out dough to about 1/4 inch thick
Cut into shapes as desired.
Polk holes in the cookies or else they will blow up fat.
Bake at 350 degrees for 30-40 minutes depending on how crispy you like them. I baked them long because I was looking for a crunchy cookie. Allow to cool completely before feeding to your canine friends.
Notes
These keep fine on the counter for a couple days. Any longer and they should go in the fridge or freezer. There are no preservatives so they will mold otherwise.