90g Arborio rice
A pinch of fine sea salt
100g vanilla sugar
60g unsalted butter
The grated zest of 2 lemons
2 large eggs (at room temperature), separated
1tbsp lemon juice
2tbsp dark rum
Icing sugar for dusting
Line 15 medium-sized muffin moulds with cupcake papers.
Bring the milk to the boil, stir in the arborio rice and salt, reduce the heat and simmer gently for 10 minutes, stirring regularly.
Add the sugar and butter and continue simmering until the rice is cooked. The rice should just be coated in the thickened milk mixture; if it's drying out during cooking then add a little more milk.
Transfer the mixture to a bowl and leave to cool for about an hour, stirring occasionally as it's cooling.
Preheat the oven to 190C/gas mark 5.
Stir the grated lemon zest, the egg yolks, lemon juice and rum into the rice. In a very clean bowl whisk the egg whites with an electric whisk until stiff, then gently fold them into the rice mixture. Spoon the mixture into the lined muffin tins to the top.
Bake the tea cakes in the oven for about 25-30 minutes until golden (you can test if they are done by inserting a skewer in the centre and if it comes out clean, they're ready).
Transfer the cakes to a wire rack for 10 minutes, then either leave the cakes in the paper or remove them and dust with icing sugar before serving.