Get a food processor when you subscribe to our print magazine
Ask a grown-up to turn the oven on to 200C/180C fan/ gas 6. Sit each apple on the worktop and push the apple corer into the centre of each one (or ask a grown-up to do this for you).
Mix the sultanas, muscovado sugar and cinnamon together in a bowl.
Stand up the apples, side by side, in a baking dish. Using your fingers, push a little bit of the sultana mixture into each apple, using up all the mixture between them.
Add a blob of butter to the top of each and sprinkle over the demerara sugar. Ask a grown-up to put the dish in the oven for 20 mins or until the apples are cooked through.