Method

Preheat the oven to 150°C fan oven/170°C electric oven. Whisk the egg whites in a large bowl with the salt and cream of tartar until stiff peaks form using an electric whisk. Whisk in the sugar, a couple of tablespoons at a time, sprinkling it over the egg whites and whisking for about 20 seconds with each addition. Fold the sifted flour into the meringue in three goes, and then the vanilla extract and lemon zest. Spoon the mixture into an 18cm unbuttered angel cake tin and bake for 40 minutes until golden and springy to the touch. Invert the pan and leave the cake to cool.

To make the icing, add just enough lemon juice to the icing sugar in a bowl to achieve a thick coating icing. Run a knife around the edge of the cake and lift it out on its base, then remove this. Place the sponge, base-side up, on a plate and smooth the icing over the top and sides using a palette knife. Leave to set for about 1 hour before transferring the cake to a stand or serving plate. To serve, scatter the blueberries over and around the cake – you can fill the hole if you wish – then dust with icing sugar.

TIP
Contrary to so much baking where we take every precaution to ensure the sponge doesn’t stick, here the case is the opposite. By not buttering the tin, cooling the sponge upside down and not running a knife around the edge first, you will preserve its lightness and shape. Remove the lemon zest with a fine or spiked grater rather than a zester, as it is the essential oil that you are after.

For a Chocolate Angel Cake, omit the lemon zest and replace 30g of the flour with sifted cocoa powder.

Extract from Annie Bell’s Baking Bible, by Annie Bell, published by Jacana.