Chocolate jaffa cakes

Serves 4 Ready in: 30 minutes, plus cooling and chilling

2 large oranges, segmented, plus grated zest to decorate 4tsp orange liqueur, such as Cointreau 400ml skimmed milk 5 large egg yolks 3 level tbsp sweetener granules 1 level tbsp cornflour ½tsp vanilla extract 25g plain dark chocolate (at least 70% cocoa), chopped, plus 5g, grated, to decorate 2tbsp fat-free natural Greek yoghurt

1 Put the orange segments into 4 x 250ml glass tumblers or ramekins and sprinkle over the orange liqueur.

2 Bring the milk slowly to the boil in a small non-stick saucepan over a medium heat, stirring to make sure it doesn’t catch on the pan.

3 Beat the egg yolks and sweetener together in a heatproof bowl until thick and pale. Beat in the cornflour. Slowly whisk in the hot milk, return the mixture to a clean pan and cook over a low heat, stirring, until the custard thickens and coats the back of a wooden spoon. Stir in the vanilla extract.

4 Pour a quarter of the custard into a bowl and set aside. Stir the chocolate into the remaining custard, return the pan to a low heat, and stir gently until the chocolate has melted. Cool slightly, then pour the chocolate custard into the tumblers or ramekins and lightly level the top with the back of a teaspoon.

5 Spoon the reserved custard over the chocolate custard, cover and leave to cool completely. Chill for at least 2 hrs or until set. Spoon a dollop of yoghurt on to each pot and sprinkle with the grated chocolate and orange zest to serve.