Angel Food Cake

Heat the oven. Heat the oven to 175°C (155°C fan) and let it come up to temperature for at least 20 minutes before baking, with a shelf set in the lower-middle position. Because this cake rises almost entirely from whipped egg whites, a properly heated oven sets the structure quickly rather than letting the foam collapse while it waits. Leave the tube tin completely ungreased and unlined, since the batter needs to grip bare metal to climb the sides.

Sift the dry mix. Sift the flour with 150g of the caster sugar three times into a bowl, tipping the mixture back through the sieve each time. Repeated sifting breaks up lumps and leaves the flour fine and airy, so it folds into the whipped whites without knocking the air back out. You should end up with a powdery mix with no visible specks.

Whip the egg whites. In a completely clean, grease-free bowl, whisk the egg whites on medium speed until foamy, then add the cream of tartar and salt and continue whisking to soft peaks. Any trace of fat left on the bowl or whisk stops whites whipping up properly, which is why spotless equipment matters so much here. The whites should hold a soft peak that just folds over when the whisk is lifted.

Build a glossy meringue. Add the remaining 150g of sugar a spoonful at a time, whisking well between additions, until the meringue turns glossy and holds a medium-firm peak that bends gently at the tip; whisk in the vanilla in the last few seconds. Adding the sugar gradually gives it time to dissolve fully, which is what makes the meringue shine and hold its shape. Stop as soon as the peaks bend rather than stand bolt upright, since overwhipped, dry whites break up and make the baked cake shrink.

Fold in the flour. Sift a quarter of the flour and sugar mixture over the meringue and fold it in with a large spatula using a few broad strokes, then repeat with the rest in three more additions. Folding rather than stirring protects the air bubbles that are the only thing giving this cake its height. Stop as soon as no streaks of flour remain — working it any further is the other common way to deflate the batter.

Fill the tin. Spoon the batter into the ungreased tin, then run a knife through it in a slow spiral to pop any large air pockets, and smooth the surface. Levelling it now means the cake bakes with an even top instead of a lopsided dome.

Bake until golden. Bake for 35-40 minutes, until the top is golden and cracked, springs back when pressed lightly, and a skewer inserted into the centre comes out dry. These signs all show the egg proteins have fully set; taking it out too early leaves a wet, collapsible middle.

Cool upside down. As soon as it comes out of the oven, turn the tin upside down onto a wire rack, or rest the central tube over a bottle neck, and leave it to cool completely for about 2 hours. Cooling it the right way up would let the delicate foam collapse under its own weight, so gravity needs to work against the cake while it finishes setting.

Release and slice. Once fully cool, run a thin knife around the sides and the central tube to loosen the cake, then push it out and slide it off the base. Cut it with a serrated knife using a gentle sawing motion rather than pressing straight down, which would crush the airy crumb, then serve with the strawberries.