You will need:
160g of fine oats
60g of cooked sweet potato
1 good sized banana
Some plain flour for dusting
Place the ingredients into a food mixer and blend together for about ten seconds.
Empty out into a bowl and, using your hands, form into a dough.
Wrap the dough in cling film and place in a fridge for at least 6 hours or overnight.
Allowing the dough to rest lets the oats absorb moisture which will prevent them swelling in the stomach.
Pre-heat your oven to 180ºC (fan). Lay the dough out on a suitable surface and roll to a thickness of approximately 1cm. Use a little plain flour to dust if the dough is a bit sticky. Cut using an appropriate cutter. Place them on a lined baking tray and bake in the oven for 30-35 minutes. When they are thoroughly cooked through, remove them from the oven and leave to cool completely. The biscuits will keep fresh in a sealed container for about a fortnight.
Test out on a willing volunteer
Of course, being a treat they are only to be given occasionally alongside a well balanced diet.