Baked Alaska

Ingredients
For the Sponge
* 50g (2oz) unsalted butter, softened, plus extra for greasing
* 50g (2oz) caster sugar
* 1 egg
* 40g (1 ½ oz) self-raising flour
* 1/4 teaspoon baking powder
* 15g (½oz) cocoa powder
* 2 tablespoons coffee flavoured liqueur
For the Topping
* 1 litre (1 ¾ pint) round tub chocolate ice cream
* 250g (8oz) plain chocolate, broken into pieces
* 75g (3oz) unsalted butter
* 4 egg whites
* 250g (8oz) caster sugar
Method
1. To make the sponge, grease and line the base of an 18cm (7 inch) round cake tin. Beat the butter, sugar, egg, flour, baking powder and cocoa powder together in a bowl.
2. Turn into the prepared tin and level the surface. Bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 20-25 minutes until just firm. Transfer to a wire rack to cool.
3. Cut the sponge in half horizontally and drizzle with the liqueur. Turn the ice cream out of the tub, keeping it in shape. Using a large knife, slice the block of ice cream in half horizontally.
4. Put one sponge layer on a flat ovenproof serving plate. Alternatively, use the base of a 20cm (8 inch) round loose-bottomed cake or flat tin so that you can lift it on to a decorative plate to serve.
5. Cover with one half of the ice cream. Cover this with the other half of the sponge, then the remaining ice cream. Trim off any excess sponge. Return to the freezer.
6. Put the chocolate and butter in a heatproof bowl set over a saucepan of barely simmering water so that the base of the bowl is not touching the water and stir lightly until melted and smooth. Quickly spread the chocolate mixture in a thin layer all over the ice cream and sponge. Return to the freezer.
7. Whisk the egg whites in a large, grease-free bowl until stiff. Gradually whisk in the sugar, a little at a time, until stiff and glossy. Spread the meringue over the chocolate sauce to cover. Make soft peaks over the meringue with the back of a spoon, then return to the freezer.
8. Transfer the Alaska to the refrigerator about 10 minutes before serving. Bake in a preheated oven, 230°C (450°F), Gas Mark 8, for 3-5 minutes until the meringue is turning golden. Serve immediately.