Step 1

Adjust the oven rack to the lower third of the oven, and preheat the oven to 350F/180C.

Step 2

Coat a 13X9-inch baking pan with non-stick cooking spray (or grease and flour), then line the bottom of the pan with a rectangular piece of parchment paper, and spray this as well.

Step 3

Sift the cornstarch and flour together in a medium bowl, and set aside.

Step 4

In the bowl of a stand mixer, using a handheld wire whisk, combine together the eggs, sugar, vanilla and salt. Set the bowl over a saucepan of simmering water (make sure the bottom of the bowl is not touching the water or the eggs could scramble). Heat, stirring constantly, until quite warm to the touch but not hot.

Step 5

Immediately remove from the saucepan and transfer to the stand mixer fitted with the whisk attachment. Beat the mixture on high speed until very thick, frothy, has dramatically lightened in color, and quadrupled in volume; about 5 minutes. In a 5-quart mixer bowl, it will come to about three-quarter high.

Step 6

When the beating is complete, sift half of the flour mixture onto the beaten eggs. With a silicon spatula, gently but rapidly, fold in the flour mixture until mostly incorporated. Be careful not to deflate all the air that has been whipped into the mixture. Repeat with the remaining flour mixture until no flour pockets remain and has disappeared completely.

Step 7

Pour the cake batter into the prepared pan and bake until deep golden brown and a toothpick inserted in the center comes out clean, 25 to 35 minutes.

Step 8

To prevent the collapse of the cake's delicate foam structure, it MUST be unmolded while still hot, as soon as its baked. So immediately run a knife between the sides of the pan and the cake, pressing firmly against the pan. Unmold right away onto a wire rack, leaving the parchment in place, then reinvent onto another wire rack, golden side up. Allow to cool completely. When cool prepare the milk mixture.

Step 9

In a large (2 quart/ 1 liter) measuring cup with a spout, whisk together the evaporated milk, sweetened condensed milk and heavy cream until well combined and smooth.

Step 10

Using a serrated knife, remove the upper crust of the cake, peeling it completely to reveal all the holes, without removing any of the cake beneath it. Invert the cake to the other side and remove the parchment. Reinvent the cake back into the baking dish.

Step 11

Slowly pour the milk mixture over the cake until completely absorbed. Cover tightly with plastic wrap and refrigerate for at least 8 hours or even better overnight.

Step 12

When ready to serve, take the cake out of the fridge for at least 30 minutes to take the chill out of it , and prepare the frosting.

Step 13

Wipe the bowl of a stand mixer with a little lemon juice to remove any traces of grease. Put the egg whites, sugar, cream of tartar (if using) and salt into the bowl. Using a handheld wire whisk, combine together.

Step 14

Set the bowl over a saucepan of simmering water (make sure the bottom of the bowl is not touching the bowl or the egg whites could cook). Heat, stirring constantly, until quite warm to the touch but not hot, the sugar granulates have completely dissolved and no longer feels grainy when you rub it between your fingers; 7 to 9 minutes. A food thermometer should register 130F/54C, if you're so keen to measure.

Step 15

Remove the bowl from the saucepan and transfer to the stand mixer fitted with the whisk attachment. Beat on high speed until very thick, stark white and glossy, holds a soft peak and is no longer warm.

Step 16

The frosting is best used right away, but will keep well covered at room temperature for up to 1 hour.

Step 17

Using a spatula, spread the frosting all over the surface of the cake to cover. Using a spoon or an offset spatula, make swirls and swoops on the frosting.

Step 18

Using a kitchen torch, toast the frosting until it reaches the desired color of brown. Alternatively, if a kitchen torch is not available, place the pan under the oven's broiler until browned. Keep a close eye on it, as to not let it burn.

Step 19

If desired, individual servings of cake can be frosted and torched one piece at a time, allowing for freshly torched cake, whenever its needed, and also for a pretty presentation.

Step 20

Cut into squares and serve cold or at room temperature; I personally prefer it somewhere in between, leaning towards room temperature. The cake is best eaten on the same day. Store leftovers covered in the fridge.