Apple and custard tart with walnut crumble topping

Method

1. For the walnut topping: process the caster sugar, brown sugar, flour, cinnamon and walnuts in a food processor until the nuts are finely ground. Add the butter and pulse to a crumble texture. Set aside.

2. For the fruit: heat the butter in a frying pan until nut brown, then add the apples and fry, tossing lightly, until softened. Add the rum-soaked raisins, cinnamon and nutmeg and mix well. Leave to cool.

3. For the custard filling: heat the milk and vanilla extract in a saucepan until just below boiling point. In a heatproof bowl, whisk together the egg yolks and sugar, then stir in the flour. Pour half the hot milk onto the egg mixture, whisking constantly, then pour the custard back into the saucepan. Heat until thick, stirring constantly.

4. Preheat the oven to 180C/gas 4. Spoon the custard into the tartlet cases, top with the fruit mixture, then scatter some of the crumble over each tartlet. Bake for 8-10 minutes, until the topping is golden. Serve warm with mascarpone cheese and berries and decorate with mint sprigs.