Step 1

Heat the oven to 180C/fan 160C/gas Whizz the butter, sugar and lemon zest until they are pale and creamy in a food processor. Add the lemon juice, yolks, flour, milk and vanilla one by one until you have a smooth batter. Whisk the egg whites until firm but not stiff, and fold the mixtures together.

Step 2

Pour into a buttered ovenproof soufflé or baking dish and put it in a baking tray half filled with hot water. Bake for 45-50 minutes until the top is lightly browned and set and there is a gooey lemon curd below. Serve hot with or without cream.