Step 1

Heat the oven to 180C/160C fan/gas Butter a 30 x 20cm deep baking dish.

Step 2

Put the butter and 250g caster sugar in a bowl and beat for 5 mins until pale and fluffy. Whisk in the eggs, then sieve over the flour and baking powder and fold in until you have a batter. Stir in the lemon zest, reserving a little for decoration.

Step 3

Spoon the sponge batter into the dish and smooth over the top.

Step 4

Mix the lemon juice with the cornflour in a heatproof bowl to make a smooth paste. Mix the remaining 130g caster sugar with 300ml boiling water in a jug, pour over the cornflour mix and whisk until smooth. Pour this over the sponge. Bake for 45-50 mins until golden and set, and the sponge springs back when touched.

Step 5

While the pudding is baking, make the lemon drizzle. Mix the icing sugar with enough lemon juice (about half of it) to create a loose consistency. Drizzle over the sponge while it’s still warm and decorate with the reserved lemon zest. Serve straightaway with cream or custard.