For the sponge

1. Heat the oven to 180C. Grease and line the base of 2 x 20cm round cake tins with baking paper. 
2. Dust tins with a little caster sugar, tipping out the excess as you go, and repeat with a dusting of flour.
3. Sift the flour and baking powder into the bowl of an electric mixer, add the softened butter, caster sugar, eggs and milk. Beat until smooth.
4. Divide the mixture between the prepared cake tins and spread smooth with a spatula.
5. Bake for 25 minutes until golden and the cake shrinks away from the sides of the tin. 
6. Stand for 5 minutes before turning out on to a cake rack to cool completely.

For the Baked Alaska

1. Line a 4-cup capacity dome-shaped bowl with plastic wrap, ensuring some is hanging over the edges. 
2. Cut 1 sponge cake to fit the base and sides of the bowl. Place ice cream in the centre, pushing it down as you fill, then cover completely with more sponge cake. 
3. Cover the bowl with the plastic wrap and place in the freezer. (Note: If you made your own sponge you will have 1 leftover, this can be frozen for another use.)
4. When you are ready to serve, heat the oven to 230C.
5. Whisk the egg whites in a clean bowl until they are stiff. Gradually add the caster sugar until the meringue is stiff and glossy.
6. Remove the bowl from the freezer and using the plastic wrap to help you, turn out the sponge and ice cream on to an ovenproof plate, or line a baking tray with baking paper.
7. Cover the whole thing with the meringue, being careful to cover completely — no gaps or holes. Place in the oven and bake until the meringue is golden brown. Keep an eye on it so it does not over-colour, about 5 minutes.
8. Serve with slices of freshly-cut mango.

Make a change

Sprinkle sponge cake in the bowl with 2 Tbsp dry sherry. In season, serve with a bowl of sliced peaches and raspberries.