Weighing the flour and sugar guarantees a billowy cake that's light and airy (and worthy of Cooking Light Test Kitchens' highest rating for taste).
1 1/2 teaspoons baking powder
1/2 teaspoon salt
8 ounces granulated sugar (about 1 cup), divided
6 ounces sifted cake flour (about 1 3/4 cups)
1 tablespoon grated orange rind
1/2 cup fresh orange juice (about 1 orange)
1 tablespoon grated lemon rind
5 tablespoons canola oil
1 1/2 teaspoons vanilla extract
3 large egg yolks
8 large egg whites
3/4 teaspoon cream of tartar
2 teaspoons powdered sugar
How to Make It
Preheat oven to 325°.
Combine baking powder, salt, 7 ounces sugar, and flour in a large bowl, stirring with a whisk until mixture is well combined.
Combine orange rind and next 5 ingredients (through egg yolks) in a medium bowl, stirring with a whisk. Add rind mixture to flour mixture, stirring until smooth.
Place egg whites in a large bowl; beat with a mixer at high speed until foamy. Add cream of tartar; beat until soft peaks form. Gradually add remaining 1 ounce sugar, beating until stiff peaks form. Gently stir one-fourth of egg white mixture into flour mixture; gently fold in remaining egg white mixture.
Spoon batter into an ungreased 10-inch tube pan, spreading evenly. Break air pockets by cutting through batter with a knife. Bake at 325° for 45 minutes or until cake springs back when lightly touched. Invert pan; cool completely. Loosen cake from sides of pan using a narrow metal spatula. Invert cake onto plate. Sift powdered sugar over top of cake.