Chocolate Angel Food Cake Recipe:
1 1/2 cups (360 ml) egg whites (you will need about 12 large egg whites)
1 1/2 cups (300 grams) granulated white sugar, divided
1 cup (100 grams) sifted cake flour
1/4 cup (25 grams) unsweetened cocoa powder (regular or Dutch-processed), sifted
1/4 teaspoon salt
1 teaspoon cream of tartar
2 teaspoons pure vanilla extract
Note: Cream of Tartar is tartaric acid and is a fine white crystalline acid salt which is a by-product of the wine-making industry. It is used when whipping egg whites to stabilize them and to prevent over beating and the whites drying out.
Chocolate Angel Food Cake: Preheat oven to 350 degrees F (180 degrees C) and place rack in center of oven. Have ready an ungreased 10 inch (25 cm) two piece tube pan.
Separate the eggs, whites in one bowl and yolks in another. Cover whites (you need 1 1/2 cups (360 ml)) with plastic wrap and bring to room temperature (about 30 minutes). Cover yolks and store in refrigerator or freezer for another use.
In another bowl, whisk or sift together 3/4 cup (150 grams) granulated white sugar, the sifted cake flour, sifted cocoa powder, and the salt.
In your electric mixer, with the whisk attachment, (or with a hand mixer) beat the egg whites until foamy. Add the cream of tartar and continue to beat until soft peaks form. Gradually beat in the remaining 3/4 cup (150 grams) granulated white sugar, a tablespoon at a time, until stiff and glossy peaks form. Beat in the vanilla extract.
Sift the flour mixture (about one quarter of the flour mixture at a time) over the egg whites, and gently fold the flour into the egg whites using a rubber spatula or wire whisk. (It is important not to over fold the batter or it will deflate.)
Pour the batter into the pan and run a metal spatula or knife through the batter to get rid of any air pockets. Smooth the top and bake in the oven for about 35 - 45 minutes or until a wooden skewer inserted in the center of the cake comes out clean and the cake springs back when gently pressed. Do not over bake. (The top of the cake will have cracks.)
Immediately upon removing from the oven invert (turn upside down) the pan. Suspend the pan by placing the inner tube on the top of a wine bottle or flat topped glass. Allow the cake to cool compleely (about 1 1/2 hours). Then run a metal spatula or knife around the sides and center core of the pan to loosen the cake and then remove the cake from the pan. Next, run a metal spatula or knife along the bottom of the pan and remove. Place onto a serving plate. The cake will keep covered for a few days at room temperature or for about a week in the refrigerator.
This cake can be eaten alone with just a dusting of cocoa powder or confectioners' sugar. Can be served with fresh berries and softly whipped cream.
I love the look of this Chocolate Angel Food Cake, both its lovely chocolate brown color and its ragged top and sides. It has a wonderful light and spongy texture to go with its sweet chocolate flavor. While this cake needs no adornment, other than maybe a dusting of powdered sugar or cocoa powder, to dress it up you could drizzle a shiny Chocolate Ganache over the top. A lovely cake served plain or with fresh fruit and softly whipped cream.
So what do we need to know to make a great Chocolate Angel Food Cake? First, an Angel Food Cake gets its rise, not from baking powder or baking soda, but solely from the air whipped into egg whites. In order to get the maximum volume from the egg whites, make sure your mixing bowl and whisk are clean, dry, and free of grease and have the egg whites at room temperature. The recipe begins with beating the whites until foamy. Then cream of tartar is added which helps to stabilize the whites. (Cream of tartar is tartaric acid and is a fine white crystalline acid salt. It can be found on the spice isle in most grocery stores. If you cannot find it you can leave it out.) Once the whites form soft peaks, the sugar is gradually beaten in, one tablespoon at a time. (Adding the sugar gradually ensures that it fully dissolves into the egg whites.) Continue to beat the egg whites until stiff glossy (not dry) peaks form. (You have probably noticed that Angel Food Cakes do use more sugar than other types of sponge cakes and this is to support and stabilize the large amount of egg whites.) At this point the sifted cake flour (sift the flour then measure it), mixed with cocoa powder (regular unsweetened or Dutch-processed), sugar, and salt (to prevent the flour from clumping), is folded into the beaten egg whites. (If you cannot find cake flour, you can use 3/4 cup (100 grams) all purpose flour (plain flour), sifted (measure the flour then sift it) or you can make your own cake flour. One cup sifted cake flour (100 grams) can be substituted with 3/4 cup (80 grams) sifted all-purpose (plain) flour plus 2 tablespoons (20 grams) "packed" cornstarch (corn flour).) The flour is gradually folded into the batter so it will not lose its volume. Quick light strokes with a rubber spatula or wire whisk are all that is needed.
The batter is then poured into an ungreased tube pan, with a removable bottom, which gives the cake support as well as making it easier to remove the baked cake. The pan is left ungreased so the batter will cling to the sides of the pan as it bakes and allows the cake to reach its full volume. The hole in the middle of the pan allows the hot air to circulate and reach the center of the cake. Unlike most cakes that are simply placed on a wire rack to cool, angel food cakes are immediately inverted so the baked cake will maintain its volume and to keep it from shrinking as it cools. A Chocolate Angel Food Cake is at its best the day it is made, although it can be stored for a few days, or stored in the refrigerator for up to a week.
Of course we need some delicious things to make with all those leftover egg yolks. You could make some custard based ice creams that everyone would enjoy, or if you are thinking about making a fruit tart this Pastry Cream makes the perfect filling, or maybe this buttery sweet Yellow Butter Cake.