Preheat your oven to 180C.
Slice your apples directly into a medium sized baking dish. Mine was 23cm in diameter
Squeeze a little lemon and sprinkle sugar and cinnamon over, then mix.
To make your sponge, whisk sugar and butter together for a couple of minutes. Then add an egg at a time and whisk, each with a little flour. Finally incorporate all the flour in using the whisk. Pour over the apples and spread with a palette knife or similar to smooth the top. There will be apples peeking out, but that's nice I think.
Bake for 40 minutes. Eat warm with cream or ice cream. Or cold is good too. I bet this doesn't last a full day in your house, it didn't in mine.