Vegan cookies with oats

I've stumbled across one of the most basic cookie recipes ever:

Preheat oven to 175°C, puree 2 very ripe bananas, mix with 160g fine oat flakes, form balls and bake for max. 15mins, rather too short than too long. Possible to mix in various nut butters, dried fruit, chocolate, cinnamon,...

I'm going to make those for the next time cookie cravings set in. What's your favourite (healthy) cookie recipe, preferably with low or no processed sugar?

PS: The original recipe is in German and can be found on this site: