Some mornings are just too busy for anything other than a "grab and go" style breakfast. I know this from experience as these breakfast slices have been munched by my 15 year old many a time on the way to school.
Preheat the oven to 200 degrees centigrade or 180 degrees centigrade if using a fan assisted oven.
Mix all of the ingredients except the sliced apple and extra ground cinnamon in a bowl.
Pour the mixture into 8 holes of a brownie tin.
Top each portion with an apple slice and a good pinch of cinnamon.
Bake for 20 minutes.
Remove from the oven but leave to cool in the tin before removing the portions and storing.