Preheat oven to 350°F / 180°C / Gas mark 4.
In a small bowl, stir chia seeds into yogurt. Set aside.
Add the 2 cups of oats to the bowl of a food processor and grind until fairly fine. (A few pieces of whole oat is ok, but not too many)
In a medium mixing bowl, combine mashed banana, yogurt with chia seeds and ground oats. Mix together with a sturdy rubber spatula or spoon until thoroughly combined. The dough will be stiff. You may have to knead the dough with the heel of your hand to incorporate the last bit of flour.
Light dust the counter or a work surface with flour, and using a rolling pin, roll out the dough to 1/8" thick and cut out treats with a 2” cookie cutter. (or use a small cookie scoop to portion treats, then flatten into a disk)
Use a
cookie stamp to decorate, if desired.
Place on a parchment-lined baking sheet and bake for 25 minutes, rotating tray halfway through baking time.
Cool completely before giving to your dog. Store treats in an airtight container in the fridge.