Tarte de Vienne (Fluffy White Frosted Yellow Layer Cake)

Directions

1. CAKE: Preheat the oven to 350°F. Use spray or butter to grease two round cake pans, 8x2 or 9x2 inches. I tend to prefer the latter. In a liquid measuring cup, mix the oil, water, and apple juice (or ginger ale or sprite or 7 up), vanilla, and the zest (if using), and set aside. In another bowl, whisk together the flour, baking powder and set aside. Using your stand mixer and whisk attachment, combine the sugar and eggs, and mix on medium-high speed until the mixture is thick and has tripled in volume. When you lift some of the mixture with the whisk and drop it back, it should look like a fat ribbon that holds its shape for a few seconds. At this point while running the mixer on medium speed, slowly and gradually add the liquid mixture. You want to do this carefully so as to minimize any deflation of the egg mixture. Switch to low spead and add the flour mixture to the egg mixture until the batter is smooth and lump-free - maybe 30-40 seconds. Divide the batter between the cake pans. Bake for about 30/35 minutes or until a toothpick inserted into the center of each cake comes out clean. Let the cakes cool in the pans for 30 minutes. I usually invert the cake and then do it a second time (so that what was the bottom of the cake when it was in the pan is again the bottom once unmolded). Let cake cool.
2. FILLING: Fill one of the cakes with guava jam (or one of your liking). I usually use 1/2 cup (8 tbsp). You may be tempted to use more but if you do that, some of the jam will tend to come out when you slice the cake.
3. MERINGUE OR FLUFFY WHITE FROSTING: Let egg whites stand at room temperature for 30 minutes. Room temperature egg whites will have more volume when beaten than cold egg whites. In a saucepan (ideally one quart), stir sugar, corn syrup and water until well mixed and set aside. In medium bowl, beat egg whites with electric mixer on high speed just until stiff peaks form. At this point, I turn the mixer off and then go to the stove to let the sugar mixture boil without stirring until candy thermometer reaches 242F. But to make sure the temperature reading is accurate, you may want to slightly tilt the saucepan so the sugar mixture is deep enough for thermometer. Turn mixer back on at medium speed, and carefully and slowly pour the hot syrup in a thin stream into the egg whites, beating constantly. Add vanilla. Switch to high speed and mix for 10 minutes or until stiff peaks form. Cover the cake with the frosting. You may have some leftover but it will depend on how much frosting you want to put on the cake.