Preheat the oven to 160°C fan and lightly grease an ovenproof ramekin
Add the oats to a blender and blitz until they start to look like flour
Next, add the cocoa powder, sugar, baking powder, egg, milk and mashed banana to the blender and mix until smooth
Fill the ramekin with two thirds of the mixture, then add the white chocolate
Cover the white chocolate with the remaining mixture. The baked oats will rise so be careful not to overfill your ramekin
Break up the Oreo and place the pieces on top
Bake in the oven for 20 mins
Remove from the oven and allow to cool for around 10 mins before eating
