Blueberry Angel Food Cake

Angel cake with the appropriate name is a real godsend when it comes to large family gatherings. Everyone likes it, almost no one is allergic to it, and it provides a light, sweet finish to a dish that too often turns you off. Fresh blueberries give the cake a purple hue, and citrus icing gives it a festive look.
Preheat the oven to 375 degrees.Sift together 1/2 cup sugar and 1 cup flour.In a large bowl, beat the egg whites with a mixer on high speed until frothy. Add the tartar and salt; beat until soft peaks form. Add 1 cup sugar, 2 tablespoons at a time, whisking until stiff peaks form.Sift the flour mixture over the egg white mixture, 1/4 cup at a time; toss to combine. Add vanilla and blueberries.Combine 2 tablespoons flour and lemon zest; stir to coat. Sprinkle with egg-white mixture; toss to combine.Spoon the batter into an ungreased 10-inch tube pan, spreading evenly. Cut the dough with a knife to form air pockets. Bake at 375 ° C for 40 minutes or until the cake begins to spring with a light touch. Turn the pan upside down; cool completely. Loosen the cake from the sides of the mold using a narrow metal spatula. Flip the pie onto a plate.To make the icing, combine the powdered sugar and lemon juice in a small bowl; mix well with a whisk. Pour over the cooled cake.