Preheat oven to 350F°/177C°. Spray a 9x13-inch cake pan with baking spray or grease with butter and flour. Set aside.
Sift the flour, baking powder, and salt into a large bowl. Set aside.
Break the eggs, then separate the egg whites from the yolk. Place in a medium bowl and add the egg whites in another bowl.
Using a hand mixer, whisk together the egg yolks, and sugar until the yolks become pale yellow.
Add the milk and vanilla extract to the egg yolk mixture. Then slowly pour the egg yolk mixture to the flour mixture; stir to combine.
Beat the egg whites at high speed until soft peaks form.
Gently fold in the egg white mixture to the batter until just combined. Do not over mix.
Pour the cake batter into the greased pan and place in the oven.
Bake for about 35 to 40 minutes or until a toothpick inserted into the center comes out clean.
In a medium bowl or pouring jar, combine evaporated milk, coconut milk, and condensed milk.
Using a wooden skewer, pierce the cake with holes then slowly pour ALL the milk all over the surface of the cake; making sure to pour near the edges and all around the cake.
Refrigerate the cake for at least an hour or overnight for the milk to fully penetrate the cake.