By far, one of the most delicate sponge cakes to come out of an oven is the angel food cake. This oh-so-tender sponge cake tends to melts in your mouth. However, that description doesn't necessarily mean this cake is challenging to make. Just three ingredients are required for the recipe; flour, sugar, and whipped egg whites. What makes angel food cake challenge is how those ingredients are respected whereas each has to be the right grade and mixed together the right way.

The secret to angel food cake

Cake flour is preferred because it has the least protein content among its milled family, though all-purpose flour can be substituted in some cases.

Protein is essential for gluten which provides a strong structure. So less protein produces less gluten and less gluten produces a more tender cake. The sugar also plays a role in the tenderizing of the cake as it weakens gluten that forms during mixing. That's why most sponge cake recipes have multiple times the sugar compared to flour. That as well as the last ingredient. Egg whites provide leavening for the sponge cake by trapping air within bubbles when denatured. On their own, however, they are too weak to maintain this aeration. That's where the sugar comes in. As described here, the sugar helps to attract moisture for maintaining the bubbles. When whipped together at high speeds, they form glossy peaks that are firm enough for leavening cakes or used for its own dessert called meringue.

The peaks can be firm or stiff depending on the amount of sugar added and the egg white/sugar ratio has to be adjusted to get the right result. Too little sugar and the meringue will remain too soft for the cake to rise. Too much and it could become too stiff for the cake's delicate structure. To play it safe, a 1:2 ratio should do fine for stiff peaks.

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Some recipes also call for an acidic ingredient like Cream Of Tartar to further denature the egg whites for the firm or stiff peaks.

Sponge cake and icing recipe

With all the explanation out of the way, its time to work on the angel food cake. The following recipe feature a sponge flavored and garnished with almonds. As stated before, this cake is pretty easy as long as the baker follows those rules to the letter.

Include is a simple icing that's also flavored with almonds.

Cake ingredients:

  • 3/4 cup cake flour
  • 1/4 cup almond flour
  • 1 1/2 cups castor sugar
  • 2 cups egg whites
  • 1 1/2 tsp cream of tartar
  • 1/2 tsp vanilla extract
  • 1/4 tsp almond extract

Glaze ingredients:

  • 1 cup icing sugar
  • 1/2 (2 oz) stick unsalted butter
  • 1 tbsp milk
  • 1/4 cup toasted almonds
  • 1/2 tsp almond extract

Cake directions:

  1. Preheat the oven to 180°C. Separate the egg whites from the eggs in a bowl and store the yolks for another recipe. In a separate bowl, sift all of the flour and half of the sugar.
  2. Using an electric mixer, Whip the egg whites with the cream of tartar on medium speed until soft peaks form. Switch to high speed and gradually add the remaining sugar until a meringue form with stiff, glossy peaks. Do not overbeat.
  3. Gently fold the flour into the meringue in stages until no lumps remain. Gently pour the batter into an ungreased angel food cake pan and tap the bottom on a flat surface to knock out any bubbles that form at the bottom of the batter. Bake in the oven for 35-40 minutes or if an inserted toothpick comes out clean.
  4. Place the cake inverted on a cake rack to cool for an hour before removing. To remove, from the pan, carefully run a sharp knife around the edges of the pan, then place a plate on top of the pan, invert it and lift the pan off. Seal and refrigerate or serve with icing and almond garnish (Read Icing instructions below).

Icing directions:

  1. In a mixing bowl, beat the icing sugar and butter together until smooth. Beat in the milk and almond extract until all are fully incorporated.
  2. To serve, apply the icing to the cake by slowly pour it around the center top of the cake, making sure it flows down both the outer and inner sides. Garnish with toasted almonds.