The best apple crumble

Preheat the oven to 180ºC, gas mark 4. To prepare the fruit, peel, core and cut the apples into large chunks – do the cooking apples and start cooking them first. Place the cooking apple pieces into a large saucepan with 1 tbsp water and the caster sugar. Cook, stirring often, for 4-5 minutes, until they start to soften, then remove from the heat.

Stir the cinnamon and chopped eating apples into the cooked apple mixture, then tip into a 26x18cm rectangular baking dish.

For the crumble topping, rub the butter into the flour with your fingertips until it starts to clump together with no large chunks of butter. Alternatively, use a food processor to pulse the ingredients together, taking care not to make the mix too fine. Stir in the sugar and oats and mix with your hands. Sprinkle the crumble topping over the fruit and bake for 30 minutes, or until golden and piping hot.

To make the custard, whisk together the egg yolks and sugar in a large measuring jug until well combined, then set aside. Pour the milk, cream and vanilla bean paste into a saucepan and heat until the mixture starts to steam.

Pour a small amount of the warm mixture into the eggs and whisk quickly to combine. Slowly add the rest of the milk and cream mixture into the eggs, whisking continuously. Return to the saucepan and warm over a low heat, stirring continuously, until the mixture thickens and coats the back of a spoon. Stir in the rum and serve with the bubbling crumble.