Tres Leche Cake from Scratch (3 Milks Cake)

1 cup all-purpose flour
1 1/2 teaspoon baking powder
1/4 teaspoon salt
5 large eggs, separate whites and yolks
1 cup sugar (use 3/4 cup in the egg yolks and use 1/4 cup when you whip the egg whites)
1/3 cup whole milk
1 teaspoon vanilla
12 oz can evaporated milk
14 oz can sweetened condensed milk
1/4 cup whole milk

For the whipped topping:
1 pint Heavy Cream , for Whipping
3 Tablespoons Sugar
1/2 teaspoon vanilla

Instructions:

Preheat oven to 350 degrees F. Lightly spray a 9x13'' pan with non-stick cooking spray.
In a medium bowl combine flour, baking powder, and salt in a large bowl. Separate the eggs into two separate bowls, egg whites in one bowl, egg yolks in another bowl.
Add 3/4 cup sugar to the bowl with the egg yolks and mix on high speed until yolks are pale yellow. Add the 1/3 cup milk and vanilla and stir.
Pour the egg yolk mixture over the flour mixture and stir just until combined, you don't over mix these ingredients, it will overdevelop the gluten.
Use electric beaters to beat the egg whites on high speed. Gradually add the remaining 1/4 cup of sugar as you mix and continue beating until stiff peaks form.
Fold egg whites into the batter gently so that you keep all the air you just whipped into the egg whites. Pour batter into prepared pan. Make sure to smooth it into an even layer.
Bake for 35 to 40 minutes, or until a toothpick inserted in the center of the cake comes out clean. Remove from the oven and allow cake to cool completely.
Combine the evaporated milk, sweetened condensed milk, and whole milk in a small bowl. Once the cake has cooled use a fork to poke holes all over the top of the cake.
Slowly pour the milk mixture over the the top of the cake, making sure to pour near the edges and all around.
Refrigerate the cake for at least 1 hour to allow it to soak up the milk.
Whip the heavy cream, sugar and vanilla until stiff peaks. Spread over the top of the cake.