place a rack in the center of the oven, and preheat to 325.
1. TO MAKE THE CAKE: place the egg whites and cream of tartar in a medium mixing bowl. Beat with an electric mixer on high speed for 2-3 minutes, until stiff peaks form. Set aside.
2. Place the cake mix, egg yolks, nector, oil, lemon juice and lemon peel in a large mixing bowl, and with the same beaters used to beat the egg whites (no need to clean them), blend with an electric mixer for 1 minute. Stop, and scrape down the sides of the bowl with a rubber spatula. Increase the mixer speed to medium, and beat for 2 minutes longer, scraping the side down if needed. The batter should look well blended. Turn the beaten egg whites out on top of the batter, and with the spatula, fold the whites into the batter until the mixture is light but well combined. Pout the batter into an ungreased 10" tube pan, smoothing the top with the spatula.
4. Bake the cake until it is golden brown and springs back when lightly pressed, 48-52 minutes. Remove the pan from the oven, and immediately turn it upside down over the neck of a glass bottle to cool for an hour. Remove the pan from the bottle. Run a long, sharp knife around the edge of the cake, and invert it onto a rack, then invert it again onto a serving platter.
5. TO MAKE THE GLAZE: Place the sugar, lemon juice, nectar, and lemon peel in a medium mixing bowl. Blend with an electric mixer on low speed for 30 seconds. Spread the glaze on the top and sides of the cake with clean, smooth strokes. Slice and serve.