The Best Angel Food Cake

Ingredients:

• 1 and 1/3 cups superfine sugar
• 1.5 tsp cream of tartar
• 1/4 teaspoon fine salt
• Whites of 12 large eggs, room temperature (see Note)
• 2 tsp vanilla extract
• 1 and 1/4 cups bleached cake flour (not self-rising), sifted (177 g)
• Berries and whipped cream, for serving
• Special equipment: a 25cm diameter biscuit mould with a tube in the middle (without non-stick coating)

Preparation:

1. Preheat oven to 160°C.
2. In a medium bowl, whisk together the sugar, cream of tartar, and salt. Place the egg whites in the bowl of a stand mixer fitted with the whisk attachment and add 2 tablespoons of water. Beat on low speed until the whites are foamy, 1-2 minutes.
3. Increase the speed to medium and gradually pour in the sugar mixture (this should take about 3 minutes). Watching closely, continue beating until soft peaks form, another 5-7 minutes. The tip of the mixture should hang over the whisk (if the peaks are straight up, you've beaten too much and the cake will collapse while baking). Add the vanilla extract and mix.
4. Remove the bowl from the stand and very gently fold in the flour with a spatula in three additions until completely incorporated. Pour the dough into an ungreased sponge pan with a tube in the center and smooth the surface.
5. Bake until the top is golden brown and springs back when lightly pressed, and a cake tester inserted into the center comes out clean, 40 to 45 minutes. Remove the cake from the oven and place it upside down on a wire rack to cool completely in the pan, about 3 hours.
6. Run a knife or small offset spatula around the edges of the pan and gently tap it on the counter to release the cake. Use a sharp, serrated knife to cut the cake (a regular knife will break it). Serve the cake with berries and whipped cream.
   
   Note
   
   Even the slightest amount of fat or egg yolk will ruin the whites and prevent them from whipping properly. Therefore, make sure the yolks are properly separated from the whites and the bowl and beaters are clean.