Put the milk, cream and vanilla pod into a large pan and bring to the boil. Remove from the heat to infuse for about 10 minutes. Add the rice and bring to a simmer, then continue to cook, stirring occasionally for about 20 minutes until the rice is soft and the liquid almost gone. In a bowl, whisk the egg yolks and 150g caster sugar until light and fluffy and pour into the rice. Cook gently for 5 minutes until thick and creamy. Stir in the Calvados and allow to cool. Put the rest of the sugar in a pan with 1 tbsp water and heat gently until the sugar caramelizes. Mix in the butter. Using a melon baller, scoop out rounds from the peeled apples and drop into the caramel. Cook for 5-6 minutes then scatter over the rice pudding.