Angel Food Cake

Steps

1. Position an oven rack in the bottom third of the oven and preheat to 350°F. Have an ungreased 9- or 10-inch tube pan (16-cup) ready. Do NOT grease it — the batter must cling to the pan walls to rise, and to hold on while cooling upside down.
2. Process the sugar in a food processor for about 1 minute, until very finely ground. Remove 1 cup (200 g) and set aside.
3. Add the cake flour and salt to the remaining sugar in the food processor. Pulse 10 times.
4. Sift the reserved 1 cup of sugar into a medium bowl; discard any large granules caught by the sieve.
5. Sift the sugar-flour mixture into a separate large bowl and set aside.
6. In a clean bowl, beat the room-temperature egg whites and cream of tartar on low speed until frothy, about 1 minute. (Room-temp whites whip fluffier — and even a trace of yolk will keep them from whipping.)
7. Increase speed to medium and add the reserved sugar 1 tablespoon at a time. Beat until soft, glossy peaks form, about 5 minutes total — NOT stiff peaks: soft peaks keep expanding in the oven, stiff ones won't rise. Add the vanilla on low speed just until incorporated.
8. Sift one-third of the flour mixture over the whites and fold in gently so you don't deflate the meringue. Repeat twice more.
9. Transfer the batter to the ungreased pan. Smooth the top, then gently tap the pan on the counter a few times or run a knife through the batter to break up large air bubbles.
10. Bake 35–40 minutes, until golden brown and a skewer inserted in the center comes out clean. Don't open the oven door while it bakes — the temperature drop can collapse the cake.
11. Invert the pan and cool the cake upside down for at least 1 hour — cooled right-side up it will collapse. If your pan has no feet, hang it over the neck of a wine bottle.
12. Once fully cool, run a thin knife around the outer edge, the center tube, and the bottom; lift the cake out and invert onto a cake stand. Slice with a serrated knife in a gentle sawing motion — pressing down squashes it.
13. Serve plain, or dust with powdered sugar just before serving with whipped cream and berries on the side (toppings applied early turn it soggy; the leftover yolks make great lemon curd). Store airtight at room temperature up to 2 days, or wrap well and freeze up to 3 months.