Devilish Angel Food Cake

I first made this for Lisa and Tim's engagement party. A cinnamon chocolate angel food cake from Cooking Light that is to die for. Really. Very light and spongy, great to serve with berries and whipped cream (or a light whipped topping). I haven't made it in a while, and don't want to mess with it here in the altitude of mile high land, but I would suggest someone here try it and tell me how great it is!

YUMMY!

Ingredients
2/3 cup sifted cake flour
1/3 cup unsweetened cocoa
1/4 cup sugar
1/2 teaspoon ground cinnamon
12 large egg whites
1 teaspoon cream of tartar
2 teaspoons warm water
1 teaspoon vanilla extract
1/2 teaspoon salt
1 cup sugar

Preparation
Preheat oven to 350°.

Sift together first 4 ingredients in a bowl, and set aside.

Beat egg whites, cream of tartar, warm water, vanilla extract, and salt in a large bowl at high speed of a mixer until foamy. Gradually add 1 cup sugar, 2 tablespoons at a time, beating mixture until stiff peaks form. Sift flour mixture over egg white mixture, 1/4 cup at a time, and fold flour mixture in gently.

Spoon batter into an ungreased 10-inch tube pan, spreading evenly. Break air pockets by cutting through batter with a knife. Bake at 350° for 45 minutes or until cake springs back when lightly touched. Invert pan; let cool completely. Loosen cake from sides of pan using a narrow spatula; revert cake onto plate.