Chocolate Angel Food Cake Recipe

Make the Cake - Gather the cake ingredients.

Make the Cake - Place the egg whites in the bowl of a stand mixer fitted with the whisk attachment. Alternatively, use an electric hand mixer. Let stand for about 30 minutes to bring to room temperature.

Make the Cake - Meanwhile, sift 1 cup of granulated sugar, cake flour, and cocoa into a medium bowl. Sift again and set aside (reserve the sifter, you will use it again). Position a rack in the center of the oven and heat to 350 F.

Make the Cake - With the mixer on medium speed, beat the egg whites until frothy.

Make the Cake - Add the cream of tartar and beat on high speed, gradually adding the remaining 1/2 cup of sugar. Continue beating for 3 to 5 minutes, until stiff peaks form. Beat in 1/2 teaspoon of salt and 2 teaspoons of vanilla extract.

Make the Cake - Sift half of the flour-cocoa mixture over the beaten egg whites and gently fold it in with a spatula until blended but still streaky.

Make the Cake - Sift the remaining flour-cocoa mixture over the egg whites and continue folding until well combined.

Make the Cake - Spoon the batter into a two-piece 9.5-inch tube pan. Run a butter knife or spatula through the batter to release any air bubbles.

Make the Cake - Bake the cake for about 38 to 42 minutes, or until a wooden skewer or cake tester inserted into the cake comes out clean.

Make the Cake - Invert the pan and cool the cake completely.

Make the Cake - Slide a knife or spatula around the pan and center tube to loosen the cake. Grasp the center tube to remove the cake from the outer pan; use a knife or spatula to release the cake from the bottom of the pan.

Make the Cake - Place the cake on a cake plate or cake stand and dust with confectioners' sugar, or frost with the optional fluffy chocolate frosting. If desired, garnish with shaved chocolate.

Make the Optional Frosting - Gather the frosting ingredients.

Make the Optional Frosting - Put the semisweet and milk chocolate chips in a heat-safe bowl; set aside.

Make the Optional Frosting - Pour the cream into a small saucepan and cook over medium heat until steaming hot. Do not let the cream boil.

Make the Optional Frosting - Pour the cream over the chocolate chips and let stand for 5 minutes. Stir until melted. If there are still lumps of chocolate, place the bowl over a saucepan of simmering water and stir until smooth. Alternatively, microwave on low in short bursts, stirring frequently, until the mixture is smooth.

Make the Optional Frosting - Let the chocolate mixture stand, stirring every 15 minutes, until cooled to room temperature, about 70 F to 75 F. Cooling will take about 1 to 2 hours.

Make the Optional Frosting - Add a pinch of salt, the vanilla, and 2 to 3 pieces of butter to the chocolate mixture. Beat with an electric mixer with whisk attachment on low speed, adding the butter a few pieces at a time until smooth and well combined. Alternatively, use a stand mixer fitted with the whisk attachment.

Make the Optional Frosting - Increase the speed to high and beat for about 4 to 5 minutes, scraping down the bowl as needed.

Make the Optional Frosting - Frost the cake, garnish with the shaved chocolate, if desired, and served.