Core the apple and chop up into about 12 equal pieces, i leave the skin on but whatever.
chop up each banana into about 5 pieces.
put all ingredients into an oven proof dish, cover with foil and bake on 190 degrees centigrade for about 45 minutes. Keep testing the fruit to see if it can be mushed together. Once it can be mushed together, do so.
this can now be put into a container and left in the fridge for a week or so (haven’t tried it for longer) and mixed into cereal, on toast in cakes etc.
just saves time chopping up a few bits each time you have cereal by doing it all on one go.