Preheat and prep: Set the oven to 350°F (175°C).
Line a baking sheet with parchment paper for easy cleanup.
Mix the wet ingredients: In a medium bowl, whisk 1/2 cup pumpkin puree with 1/2 cup natural peanut butter and 1 egg until smooth.
Add the dry ingredients: Stir in 1 cup rolled oats and 3/4 cup whole wheat flour. If using, add 1 tablespoon ground flaxseed and a tiny pinch of cinnamon.
Adjust the dough: The dough should be soft and slightly sticky but workable. If too wet, add a tablespoon of flour at a time.
If too dry, sprinkle in a teaspoon of water.
Shape the rounds: Scoop about 1 tablespoon of dough and roll into a ball. Place on the baking sheet and flatten gently to about 1/4–1/3 inch thick. Repeat, spacing the rounds about 1 inch apart.
Bake: Bake for 14–18 minutes, until the edges look set and the tops are dry.
For a softer treat, pull them closer to 14 minutes. For firmer treats, go toward 18 minutes.
Cool completely: Let the rounds cool on the sheet for 5 minutes, then move to a rack. Cool fully before serving to your dog.
Portion and serve: Offer 1–2 treats for small dogs, 2–3 for medium dogs, and up to 4 for large dogs, adjusting for your dog’s size and daily calories.