Position the oven rack in the lower third of the oven and preheat oven to hot 450°F. Grease the jellyroll/sheet pan and line it with parchment and then grease it again and flour it. You may use baking spray with flour included if desired.

In a small bowl, whisk together the cake flour and cornstarch.

Separate 2 of the eggs, placing the yolks in one large mixing bowl and the whites in another.

To the yolks, add the additional yolk, the 2 remaining eggs, and ½ cup of the sugar.

Beat the yolk mixture with the paddle attachment on high speed for 5 minutes or until thick, fluffy and tripled in volume. Beat in the vanilla. I placed a towel over mine because it was splattering. See photo below.

Sift ½ the flour mixture over the egg mixture and fold it in gently but rapidly with a large balloon whisk (see notes), slotted skimmer spoon or rubber spatula until the flour has disappeared. Repeat with the remaining flour mixture.

Beat the egg whites with the whisk attachment until foamy, add the cream of tartar and beat until soft peaks form when the beater is raised. Beat in the remaining 1 tablespoon of sugar and beat until stiff peaks form when the beater is raised slowly. Fold the whites into the batter and pour into the prepared pan, using an angled/offset metal spatula to level it.

Bake for 7 minutes or until golden brown, a cake tester comes out clean, and the cake is springy to the touch.

While the cake is still hot, follow instructions in the Charlotte Royale recipe about cutting a base and rolling the cake.