Preheat the oven to 350°F (180°C) then grease a 9x13 inch (23 x 33 cm) cake pan. Set aside.

In a medium bowl combine the flour, baking powder and salt. Set aside.

In the bowl of a stand mixer fitted with a whisk attachment, whisk the egg yolks on high speed for 30 seconds. Slowly stream in ¾ cup (6 oz/170 g) sugar into the bowl and continue to whip until thick and pale in color, about 3 minutes.

Lower the speed to medium and add the milk and vanilla.

Turn the speed to low and add in the dry ingredients. Gently mix until just combined. Transfer mix to a clean bowl and then wash and dry the mixing bowl and whisk attachment. Reattach the whisk attachment.

Add the egg whites to the mixer bowl whip on high speed until light and foamy. Gradually add the remaining ¼ cup (2 oz/57 g) granulated sugar and continue whipping to stiff, glossy peaks.

Using a metal spoon, gently fold the ⅓ of the egg whites into the egg yolk batter to loosen it, then fold in the remain egg whites until just combined.

Pour the batter into the prepared baking pan. Bake for 35 to 40 minutes, or until a toothpick inserted in the center of the cake comes out clean. Leave in the pan and set aside.

Make the Tres Leches Syrup

In a large measuring jug with a pour spout, combine the evaporated milk, condensed milk and whole milk and stir until well mixed. Set aside.

Use a toothpick to poke holes all over the cake. Poke the holes almost to the bottom but try not to poke all the way through. Slowly pour the syrup over the top of the cake, making sure to pour near the edges and all around. (I do this in two stages until it's all soaked up.)

Cover and refrigerate the cake for at least 1 hour but preferably overnight to allow it to soak up the milk.

Make the Whipped Topping

When ready to serve, whip the heavy cream to stiff peaks. Smooth the whipped cream over the top of the cake. Sprinkle cinnamon on top and enjoy!

This cake will keep covered in the refrigerator for up to 3 days.