A very traditional Hispanic cake. Nobody knows who came up with the idea. Some people think that it was in mexico or Nicaragua. This cake is very popular in Ecuador as well. 
Whoever did it, I am very jealous.
This is my sister Leticia's recipe with a tiny change.
Cake
1 cup all-purpose flour, sifted
1 pinch  
salt
1/2 cup sugar
1 1/2 teaspoons baking powder
6 large eggs, egg whites 
and egg yolks, separated 
1 teaspoon vanilla extract 
Mixture 
of Milks
1 can 14 ounces sweetened condensed milk
1 carton (1/2 pint) heavy whipping cream
1 can 12 ounces evaporated milk
Frosting
1/2 pint whipping cream
2 tablespoons powdered sugar OR
1 container of Cool Whip
Cake 
Preheat the oven to 350 F for 20 minutes. Grease a rectangular Pyrex 13 x 9 inches (33cm x 23cm) A little bit smaller baking pan works well, too.
Beat egg 
whites with a pinch of salt until slightly thick; add sugar and beat until very 
stiff and glossy.
Add the egg yolks one at a time beating well after each 
addition. Stir in the vanilla.
By hand, add the mixture of sifted flour and baking powder to the egg 
yolk mixture little by little folding it in. Do not overmix.
Immediately, pour the mixture in the baking pan and bake it in a preheated 350 F 
oven for about 10-15 minutes, depending on the oven or until the cake is done 
(insert a skewer in the center of the cake to see if it comes out clean) 
While the cake is baking, mix the three types 
of milk in a bowl using a whisk. Once the cake is ready and very hot; take it out of the oven 
and start making a lot of holes with a fork, trying not to 
break the bottom of the cake. Then, using a ladle, add the milk mixture to the 
cake evenly and quickly so that the whole cake can absorb all the milk; try 
to separate the sides of the cake (from the baking pan) very carefully using a 
knife in such a way that some milk goes to the bottom also. 
Let it 
stand for 15 minutes. Cover it with plastic film and put it in the fridge for many hours though it is better overnight.
A couple of hours before serving, frost the cake with some Cool Whip or home -made sweetened whipped cream (beat the whipping cream until thick adding the sugar). Decorate with fruit of your choice.
Store in the refrigerator.
Makes 12 servings