American Sponge Cake: Preheat
oven to 350 degrees F (180 degrees C) and place rack in center of oven. Have ready an ungreased two-piece 10 inch (25 cm) tube pan.
the cold eggs, placing the yolks in one bowl and the whites in another
bowl. Cover the bowls with plastic wrap and bring the eggs to room temperature (about 30 minutes).
sift or whisk the sifted flour with the baking powder and salt. Set aside.
the egg yolks and 2/3 cup (135 grams) of the sugar in the bowl of
your electric mixer, fitted with the paddle attachment (or use a hand mixer). Beat
on high speed until they are thick, fluffy and light
colored (when you slowly raise the beaters the batter will fall back into the
bowl in a slow ribbon). Then beat in the vanilla extract, water, and
lemon zest. Set aside while you beat the egg whites.
In a clean bowl, with the whisk
attachment, whip the egg whites until foamy. Add the cream of tartar and
continue beating until soft peaks form. Gradually add the 1/3 cup (65
grams) of sugar and continue beating until the egg whites are shiny
and just form stiff peaks.
Next, sift the flour mixture over the beaten egg yolks (about one third of the flour
mixture at a time) and gently but quickly fold (with a wire whisk or rubber
spatula) the flour into the egg yolk batter.
Then gently fold a little of the beaten egg whites into the batter to lighten
it, and then add the rest of the whites, folding just until incorporated.
(Do not over mix the batter or it will deflate.) Pour
the batter into the tube pan, smoothing the top.
Bake in preheated oven for
28 - 35 minutes or
until a toothpick inserted into the center of the cake comes out clean. Remove
from oven and immediately invert the pan (turn upside down) and suspend it by
placing the inner tube on the top of flat topped glass or bowl. Allow the cake
to cool completely before unmolding (about one hour). Run a flat metal spatula or sharp
knife around the inside of the pan and then remove the center core of the
pan. Run the spatula along the bottom and center core of the pan. Invert the
cake onto a greased wire rack. The cake can be served plain with a dusting of
powdered sugar or with fresh fruit and softly whipped cream. This cake can be
covered and stored for a few days, or it can be frozen. Serves about 10 people.