"I Can't Believe This is a Passover Cake" Yellow Cake

Preheat oven to 350 degrees.
Generously grease a 10 inch spring-form pan or a 9x13 inch rectangular pan. Dust with potato starch and line the bottom with parchment paper.

Warm the eggs (still in their shells) by placing them in a bowl and covering them with very hot water for 1-2 minutes (the water should be hot enough to warm them up, but not so hot as to crack the eggs and cook them. Do not leave eggs in water longer than 1-2 minutes).

This is the most important step. Do not omit it. Heat mixing bowl by filling with very hot water and then dry completely.

Meanwhile, sift together the cake meal, potato starch, and 1/4 teaspoon salt. Combine the lemon juice and melted margarine or oil in a small bowl. Set these ingredients aside.

Break the warmed eggs into the bowl of an electric mixer along with granulated sugar, vanilla sugar, 1/4 teaspoon salt, and citrus zest. Using a whip attachment beat on low speed very briefly, just to combine ingredients. Then increase to high speed and beat for 12 minutes. The batter will be extremely voluminous.

Pour the batter into a very large mixing bowl. Stir in the potato starch/matzo cake meal mixture, and then gently fold this mixture into the egg batter, taking care not to deflate the mixture too much (some deflation is impossible to avoid). Gently drizzle and fold in the lemon juice and melted margarine or oil. Pour the batter into the prepared pan and bake for 30 to 35 minutes, until the cake is set in the center or until it seems just firm when lightly touched. Cool well before removing from the pan.