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

Add the sourdough starter, whole wheat flour, rolled oats, egg, peanut butter, and pumpkin puree or applesauce (if using) to a medium mixing bowl.

Stir with a sturdy spoon until the dough begins to come together into a shaggy mass.

Use your hands to knead the dough in the bowl until it becomes smooth and firm, adding a teaspoon of flour at a time if it is sticky or a few drops of water if it is very dry and crumbly.

Lightly flour a clean work surface with whole wheat flour and place the dough on it.

Roll the dough out with a rolling pin to about 1/4-inch thickness.

Use small cookie cutters or a knife to cut the dough into bite-sized shapes that are appropriate for your dog’s size.

Transfer the cut pieces to the prepared baking sheet, spacing them slightly apart.

Press a few extra rolled oats lightly onto the tops of the treats if desired for added texture.

Bake in the preheated oven for 25 to 30 minutes, or until the treats are firm and lightly golden on the bottoms.

Turn off the oven and let the treats sit inside for 5 to 10 minutes if you want them extra dry and crunchy.

Remove the baking sheet from the oven and let the treats cool completely on the pan before serving to your dog.

Store the cooled treats in an airtight container at room temperature for up to 5 to 7 days, or freeze for longer storage.