1 1/4 c sifted cake-and-pastry flour (sift before measuring) .
2 tbsps cake flour .
2 tbsps sugar
Directions
Step #1 Make White Batter:.
Step #2 Let whites warm to about room temp.
Step #3 I like to let them warm in the shell because the whites separate easier from the yokes.
Step #4 Sift 1-1/4 c flour with 1/2 c sugar.
Step #5 Resift three times.
Step #6 (I do it on waxed paper).
Step #7 With electric mixer at high speed, beat whites with salt & cream of tartar until soft peaks form when beater is slowly raised.
Step #8 Beat in 1 c sugar, 1/4 c at a time beating well after each addition.
Step #9 Beat until stiff peaks form.
Step #10 With wire whisk, fold vanilla into egg whites until mixd.
Step #11 Sift flour mixture, one fourth at a time, over egg whites.
Step #12 With wire whisk, using an under-and-over motion, carefully fold in each addition with 15 strokes, rotating bowl a quarter of a turn after each addition.
Step #13 Fold ten more strokes to mix completely.
Step #14 Turn 1/3 batter into medium bowl.
Step #15 Preheat oven to 375°F.
Step #16 Make Yellow Batter:.
Step #17 In a small bowl, mix yolks, cake flour & sugar.
Step #18 With mixer at high speed, beat until very thick.
Step #19 Add lemon peel.
Step #20 With wire whisk, using an under-and-over motion, fold yolk mixture into reserved one third batter with 15 strokes.
Step #21 For marbling effect, spoon batters alternately into an ungreased 10" tube pan, ending with white batter on top.
Step #22 With knife, cut through batter twice.
Step #23 With rubber scraper or knife, carefully spread batter in pan until it is smooth on top & touches side of pan all around.
Step #24 Bake on lower oven rack 35 to 40 mins, or until cake springs back when pressed with fingertip.
Step #25 Invert pan over neck of bottle to cool 2 hrs.
Step #26 My tube pan has 3 spokes sticking up so it can be inverted without the bottle.
Step #27 With spatula or knife, loosen cake from pan, remove & sprinkle with confectioners sugar.