Preheat the oven to 350 degrees Fahrenheit. Grease a 12-cup capacity bundt pan with vegetable shortening. Dust the greased areas with flour and tap off excess. Set aside.
In a medium mixing bowl, combine the sifted cake flour, baking powder, fine salt and lemon rind. Set aside.
In a large mixing bowl, using an electric mixer, cream the butter until light and fluffy. Gradually add the sugar while beating the butter at medium speed. After adding all of the sugar, increase the speed of the mixer and continue to beat for 5 minutes or until the mixture becomes very pale. This step is very important so that the sugar does not settle in the bottom of the cake. Add the egg yolks to the butter mixture. Beat at medium speed until blended. Alternately add the dry ingredients and the milk to the butter mixture, beating well after each addition. Start and end with the dry ingredients. Set aside.
In another mixing bowl, pour in the egg whites and the cream of tartar. Beat at medium speed until frothy. Gradually add the remaining sugar while continuing to beat at medium speed. After adding all of the sugar, increase the speed of the mixer and continue to beat until the egg whites are stiff and still glossy.
Carefully fold the beaten egg whites into the butter mixture. Transfer to the prepared baking pan. The baking time will be approximately 1 hour and 10 minutes. Insert a cake tester in the center of the cake to check doneness. It should come out clean.
Invert cake onto a wire rack and apply fresh lemon glaze immediately using a pastry brush.
To prepare glaze, combine lemon juice and sugar. Mix with a spoon and use immediately.
