To prepare Sunshine Cake: In a very large bowl, allow egg whites to stand at room temperature for 30 minutes. Meanwhile, sift cake flour and ¾ cup of sugar together 3 times.
Preheat oven to 375°F. Add vanilla and cream of tartar to egg whites; beat with an electric mixer on medium to high speed until soft peaks form (tips will curl). Gradually add the remaining ¾ cup sugar, beating until stiff peaks form (tips will stand straight). Sift about ¼ of the flour mixture over the egg white mixture; fold in gently. Repeat sifting and folding in with the remaining flour mixture, using ¼ of the flour mixture each time. Transfer half of the egg white mixture to another bowl; set both bowls aside.
In a medium bowl, beat egg yolks with an electric mixer on high speed for about 5 minutes or until thick and lemon-colored. Fold egg yolk mixture into one portion of the egg white mixture. Alternately spoon dollops of yellow and white batters into an ungreased 10-inch tube pan. Gently cut through the batters with a knife or a narrow metal spatula.
Place tube pan on the lowest oven rack. Bake for 35 to 40 minutes or until cake springs back when lightly touched near center. Immediately invert the cake in the pan, standing the center tube over a tall-neck bottle. Cool thoroughly. Loosen cake from pan; remove cake.
To prepare Lemon Fluff: Thaw dessert topping. Fold lemon peel and lemon juice into thawed dessert topping. Add more peel and/or juice for a more intense flavor. Frost cake with Lemon Fluff. If desired, garnish with raspberries and orange and/or lemon peel strips. Store cake in refrigerator.