Ingredients
7 large eggs, separated, room temperature2 cups all-purpose flour1-1/2 cups sugar3 teaspoons baking powder1 teaspoon salt3/4 cup water1/2 cup canola oil4 teaspoons grated lemon zest2 teaspoons vanilla extract1/2 teaspoon cream of tartarFROSTING:1/3 cup butter, softened3 cups confectioners’ sugar4-1/2 teaspoons grated lemon zest1/4 cup lemon juiceDash salt
Preparation
Preheat oven to 325°.
Sift flour, sugar, baking powder and salt together twice; place in another large bowl. In a small bowl, whisk egg yolks, water, oil, lemon zest and vanilla until smooth. Add to flour mixture; beat until well blended.
Add cream of tartar to egg whites; with clean beaters, beat on medium speed just until stiff but not dry. Fold a fourth of the whites into batter, then fold in remaining whites.
Gently spoon batter into an ungreased 10-in. tube pan. Cut through batter with a knife to remove air pockets. Bake on lowest oven rack 50-55 minutes or until top springs back when lightly touched. Immediately invert pan; cool completely in pan, about 1 hour.
Run a knife around sides and center tube of pan. Remove cake to a serving plate.
In a small bowl, combine frosting ingredients; beat until smooth. Spread over cake.
