Put everything into a small mug and mix well making sure all the oats are combined from the bottom of the mug. If you've got a blender, blitz oats to a powder for a few seconds as it makes the texture more cake-y.
Microwave on high for 90 seconds (or transfer into an oven-proof dish and cook in the oven for 15 minutes on 180C/ 350F/gas mark 4).
Tip the cake out onto a plate, top with extra yogurt and enjoy straight away
