This doesn’t fill up a whole mug with Oreo cake. In order to do so, you would need to double the recipe. However, this is very rich, so only using five Oreos is probably all you need to satisfy your chocolate cravings. Regardless, feel free to double the recipe if you want a whole mug worth of Oreo cake. If you decide to double the recipe, make sure to use a larger mug. If you have too much batter, it can overflow in the microwave.