Peel, core and cut the apples into 5mm cubes.
Mix the apples with the rest of the filling ingredients and place them in individual ramekins or in a large baking dish (mine is 28cm/11in in diameter). Press down gently to minimize the amount of air between the apples.
Sprinkle the crumble on top.
Bake in a preheated oven at 180°C/350°F for 30-40min or until golden on top and bubbly. If you have an electric oven, you can see how it's going at the 20min mark and if it's already golden enough on top, switch to bottom heat only for the rest of the cooking process.
Let it cool down completely before serving.