Preheat your oven to 350°F (175°C).

In a mixing bowl, combine the mashed bananas, rolled oats, and peanut butter until well mixed.

Gradually add the whole wheat flour, mixing until a dough forms.

Roll out the dough on a floured surface to about 1/4 inch thick.

Use cookie cutters to cut out shapes and place them on a baking sheet lined with parchment paper.

Bake in the preheated oven for 20-25 minutes, or until golden brown.

Let the treats cool completely before serving to your dog.