2Separate the yolks into a medium/largish bowl (or the bowl of a stand mixer).
3Using a hand blender, beat the yolks on high speed.
4Slowly add 3/4 cup (165 grams) of granulated sugar gradually until all the sugar is added and the mixture is light.
5Beat in 3/4 teaspoon (2 grams) of vanilla extract and 1/2 cup (120 milliliters) of whole milk until thoroughly combined.
6Separately, beat the egg whites on high speed until they begin to turn frothy.
7While continuously beating, add 1/4 cup (55 grams) of granulated sugar in batches until all the sugar is added.
8Keep beating until you get nice medium stiff peaks.
9Fold the egg yolk mixture and egg white mixture together until you get a homogenized pale yellow mixture.
10Separately, whisk together 1 1/2 cups (225 grams) of all-purpose flour, 1/2 teaspoon (3 grams) of fine sea salt, and 1 1/2 teaspoons (7 grams) of baking powder until thoroughly combined.
11Add the flour mixture to your fluffy mixture and fold together until thoroughly combined, creating a sponge cake batter.
12Prepare a 9x13 baking pan by spraying it with non-stick cooking spray or greasing with butter.
13Pour the sponge cake batter into the prepared pan.
14Bake in the oven at 350 degrees Fahrenheit (175 degrees Celsius) for 25 to 30 minutes, or until a toothpick inserted comes out clean.
15Place the cake aside and let it cool completely.
16To make evaporated milk from scratch, take 3 1/2 cups (820 milliliters) of whole milk and put it in a medium-sized sauce pot.
17Place it on the stove and lightly simmer, stirring occasionally, for 25 minutes or until reduced to about 1 1/2 cups (350 milliliters).
18In a medium-sized bowl, add 14 ounces (400 milliliters) of sweetened condensed milk, 12 ounces (350 milliliters) of evaporated milk, beans from one vanilla bean (optional), and 1/2 cup (120 milliliters) of heavy cream.
19Whisk the milk mixture together until thoroughly combined.
20Grab your cooled sponge cake and prick the entire cake with a fork, being careful not to rip the cake.
21Pour all of your triple milk mixture on top of your sponge cake.
22Cover it with plastic wrap and place it in the fridge for at least one hour, ideally overnight, for the milk to soak in and evenly disperse.
23To make dulce de leche, in a medium-sized sauce pot, combine 4 cups (1 liter) of whole milk and 1 1/4 cup (270 grams) of granulated sugar.
24Mix the sugar and milk together, then place it on your stove over medium-low heat.
25Let the sugar dissolve, and as soon as it comes to a simmer, reduce the heat to medium-low.
26Gently simmer and reduce while stirring often for about 1 1/2 hours, or until thickened and a nice deep brown, being careful not to let it burn.
27Once done, take the dulce de leche off the stove and let it cool to room temperature.
28Pull your fully moisturized cake from the fridge.
29Add a generous amount of your dulce de leche on top, saving any unused portion.
30Spread the dulce de leche evenly all over the top of the cake.
31Separately, whip 1 cup (240 milliliters) of heavy cream with 1 tablespoon of granulated sugar until you get a beautiful fluffy whipped cream.
32Spread all of your whipped cream on top of your soaked tres leches cake.
33Gently sprinkle some ground cinnamon all over the top of your cake, going lightly.
34Serve the cake ice cold.
35Take a nice sharp knife and cut the cake into 12 even squares.
36Plate your cake and optionally add some macerated strawberries (strawberries sliced, tossed in a few tablespoons of sugar, and left to sit for a minute or two until juices come out).
37Spoon the macerated strawberries on top, dig in, and enjoy.