Preheat the oven to 350 degrees F. Grease a 9x13-inch pan and set aside.
In a large bowl, whisk together flour, baking powder and salt. Set aside.
In a stand-up mixer with paddle attachment, beat egg yolks and sugar until pale yellow and double in volume. Mix in the vanilla and the milk on low speed just until combined, then fold the egg yolk mixture into the flour mixture.
In a clean mixing bowl, add the egg whites and beat with the whisk attachment on high until stiff peaks about 3 to 4 minutes.
In two batches, fold the egg white mixture into egg yolk and flour mixture until you no longer see any bits of egg white.
Pour the batter into the cake pan and bake for 18 to 20 minutes. Cool the cake in the pan for about 30 minutes.
Assemble & Topping:
In a large serving bowl or measuring cup, whisk together the sweetened condensed milk, evaporated milk and whole milk.
When the cake is cool, using a fork, poke holes in the top of the cake. The more holes the better absorption. Pour the milk mixture over the cake. Transfer to the fridge to 2 to 3 hours, ideally overnight.
Just before serving, make the whipped cream. In a bowl, using an electric mixer or hand whisk, mix the heavy cream, powdered sugar and salt until soft peaks form. Top the cake with the fluffy whipped cream. Garnish with a bit of ground cinnamon.
This cake stays good for about 3 days when stored in the fridge.