Heat oven to 200c/fan 180c/gas 6. Put the apples into a saucepan with a splash of water, cover, then cook for 5 minutes until just soft. Stir in 3 tbsp of the caramel, then tip into an ovenproof dish. Dot some more caramel over the top.
Mix the flour and oats, then rub in the butter until you have a crumbly mixture. Stir in the rest of the caramel, then scatter over the apples. Bake for 20 minutes until golden and crisp on top.