Does angel food cake have to have powdered sugar?!
Just find a recipe that does not call for xxx sugar. I would not sub granulated sugar for xxx sugar, though. Won't turn out the same.
Lemon Angel Food Cake
2 cups granulated or superfine sugar, divided
1 1/3 cups sifted cake flour (not self-rising)
1? cups egg whites, at room temperature (10 to 12 eggs)
3/4 tsp kosher salt
1? tsp cream of tartar
3/4 tsp pure vanilla extract
1? tsp grated lemon zest (2 lemons)
Preheat the oven to 350o F. Combine 1/2 cup of sugar with the flour and sift together 4 times. Set aside.
Place the egg whites, salt, and cream of tartar in the bowl of an electric mixer fitted with a whisk attachment and beat on high speed until the eggs make medium-firm peaks, about 1 minute. With the mixer on medium speed, add the remaining 1 1/2 cups of sugar by sprinkling it over the beaten egg whites. Whisk for a few minutes until thick and shiny. Whisk in the vanilla and lemon zest and continue to whisk until very thick, about 1 more minute. Sift about 1/4 of the flour mixture over the egg whites and fold it into the batter with a rubber spatula. Continue adding the flour by fourths by sifting and folding until it's all incorporated.
Pour the batter into an ungreased 10-inch tube pan, smooth the top, and bake it for 35 to 40 minutes, until it springs back to the touch. Remove the cake from the oven and invert the pan on a cooling rack until cool.
--Barefoot Contessa Family Style cookbook
You probably shouldn't substitute because it will affect the texture. But you could always google another recipe. My mother never used powdered sugar in her angel cake