• 2 cups flour
• 1 1/2 cups sugar
• 1 tablespoon baking powder
• 1 teaspoon salt
• 3/4 cup water
• 7 egg yolks
• 1/2 cup vegetable oil
• Grated zest of 2 lemons
• 2 teaspoons vanilla
• 8 egg whites
• 1/2 teaspoon cream of tartar
• 1 1/2 cups confectioners' sugar
• 2 tablespoons plus 1 teaspoon fresh lemon juice
• 2 tablespoons melted butter
• 1 teaspoon grated lemon zest

Preheat the oven to 325°. In a large bowl, combine the flour, sugar, baking powder and salt. Make a well in the center; add the water, egg yolks, oil, lemon zest and vanilla. Whisk the dry ingredients into the yolk mixture until the batter is blended and smooth. Set aside.

In a large mixer bowl, beat the egg whites and the cream of tartar at medium-low speed until foamy. Gradually increase the speed to high and beat the whites until stiff (but not dry) peaks form. Gently fold 1/3 of the beaten whites into the batter with a rubber spatula just until blended. Fold in the remaining whites just until combined. Pour the batter into an ungreased 10-inch tube pan.

Bake 1 hour, or until the top springs back when lightly touched with a fingertip and a cake tester inserted into the center comes out clean. Immediately invert the cake, still in the pan, onto the neck of a wine bottle or a large funnel. Cool completely.

In a medium bowl, whisk together the remaining ingredients until smooth.

Remove the cake pan from the bottle. Run a long thin knife around both edges of the cake pan. Invert the cake onto a serving plate and remove the pan. Spread the icing on top of the cake, allowing some of the glaze to drip down the sides.