Successfully making vanilla genoise

This cake is the most delicate and difficult cake to make successfully. Well, in my ever so humble opinion anyway! I believe that if you are armed with the tricks and tips to making it correctly you can and will be successful!! It may take a couple of times making it, but do not get discouraged. Part of what makes this cake difficult is that you need to know what to look for and if you haven't made it... So I will provide some photographs to help you understand what it is you need to know about this fine and delicate batter.
I don't want to scare you, only give you the info you need to make it work but somehow in imparting these directions I tend to freak folks out so I am putting out a disclaimer right now...this is NOT my intention :)
Here is the formula and following will be the detailed but not scary instructions:
I am using Rose's formula since it comes out so beautifully light and airy, not the typical dry and grainy of the classic genoise. But I have added some of my tips on making a perfect genoise.

3 tablespoons unsalted butter, melted (or browned for that extra nutty flavor)
1 teaspoon vanilla
4 large eggs
1/2 cup fine sugar
1/2 cup sifted cake flour (sift before measuring)
1/2 cup minus one Tablespoon sifted cornstarch (again sift before measuring)
Now sift the two together.

For this cake you will need two 9" x 2" round cake pans coated with baking spray and the bottom lined with parchment paper.
Preheat the oven to 350F
Melt the butter, add the vanilla and keep warm.

Place the eggs and sugar in a metal bowl and combine with a whisk. Place the bowl with the eggs and sugar over a pan of simmering water. With the whisk, stir the eggs constantly until they reach about 100F which is just above body temperature. Make sure the sugar has broken down and you can tell this by rubbing a bit of the batter between your thumb and first finger to see if you can feel any sugar granules. If you do then continue stirring just a minute or so more making sure you don't curdle the eggs by over heating them.

Attach the whip to your standing mixer and whip the mixture on high speed for about 5 minutes or until quadrupled in volume, it should look very thick and airy and make a ribbon when the whip is pulled out of the batter.

Remove almost one cup of the egg mixture and whisk it into the melted butter.
Sift about half the flour mixture over the eggs and with a balloon whisk or spatula gently but rapidly fold in the flour. Repeat until all the flour has been folded in. Be very careful to not overmix at this point. You do not want to deflate the eggs mixture. Now gently fold in the butter mixture just until incorporated. When you are folding make sure you reach all the way to the bottom of the bowl to ensure you have mixed all the flour in. Make sure all the traces of flour have been mixed in... but again, do not over do it! When you stop seeing flour, stop folding! Gently pour the cake batter into the prepared pan. Do not move the batter about in the pan. It will fall out and it should fill the pan about 3/4 of an inch to the top if you haven't deflated the eggs.

Bake for 20 - 30 minutes or until the cake is golden brown and starts to pull away from the sides of the pan. Avoid opening the oven door for the first 20 minutes. Test toward the end of the baking time and just crack the oven door a bit to peak in and see if it is done. Touch the center of the cake with one finger if it leaves a finger print it is not done. Leave it in for 5 more minutes.
When the cake comes out of the oven, run a small paring knife between the sides of the pan and the cake to release the cake from the pan. Invert the cake onto a wire cooling rack. Cool completely. It should be 2" high with a nice flat top.
This is a most versatile cake. It loves cake syrups with flavorings such as Grand Marnier or lemon juice. It goes well with soft icings like whipped cream. curds or mousse fillings. Have fun and make a cake today!