1 cup unsalted butter, softened
2 cups granulated sugar
6 eggs, separated
2 teaspoons lemon zest
1 teaspoon lemon extract
3 cups cake flour
1 teaspoon baking soda
1 teaspoon salt
1 cup plain yogurt, whole or lowfat

Preheat oven to 350 degrees. Grease and flour a 10-inch tube pan. Cream together the butter and 1 1/2 cups sugar until light and fluffy, about 6 minutes, with an electric mixer at high speed. Add egg yolks, lemon zest, and lemon extract and beat until thick and pale yellow. In a separate bowl sift the flour, measure again, and sift a second time with baking soda and salt. Stir 1/3 flour mixture into batter. When well incorporated, add half the yogurt. Add half of remaining flour mixture, followed by remaining yogurt. When incorporated, end with remaining flour mixture. Stir until blended and set aside. In a clean bowl beat egg whites until soft peaks form. Gradually add remaining 1/2 cup sugar and beat until glossy. Stir 1/4 cup egg whites into batter. Fold lightened batter into remaining egg whites. Pour batter into prepared pan and bake in preheated oven 45 minutes, or until done. Cool cake 15 minutes in pan before turning out onto wire rack to cool completely.

Lemon Glaze

2 cups powdered sugar
2 tablespoons butter, melted
5 to 6 tablespoons lemon juice
1/2 teaspoon vanilla extract
1 tablespoon lemon zest, for garnish

Sift powdered sugar into melted butter. Add lemon juice and vanilla and stir until smooth. Add more lemon juice or water to desired consistency. Immediately pour over cooled cake, allowing glaze to drizzle down the side. Garnish with lemon zest. Serves 12 to 16.