Make the Vanilla Sponge Cake:

1. Prep the pan: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking dish or ceramic pan and lightly flour, tapping out any excess. Set the prepared pan aside.
2. Mix the dry ingredients: In a large bowl, whisk together the flour, baking powder, and salt. Set the dry ingredients aside.
3. Separate the eggs: Separate your eggs into two clean mixing bowls. Make sure the bowl for your egg whites is completely clean and free of any grease or oil. Even a tiny trace of egg yolk can prevent the whites from whipping up to those beautiful, fluffy peaks.
4. Beat egg yolks: Beat the egg yolks with ¾ cup of the sugar on high speed until the egg yolk mixture is thick, pale yellow, and forms a ribbon when the beaters are lifted, about 3 to 4 minutes.
5. Add the milk and vanilla: Add the whole milk and vanilla extract and mix until just combined.
6. Fold in the flour mixture: Pour the egg yolk mixture over the flour mixture and fold gently with a rubber spatula until no dry streaks remain. The cake batter will be thick. Stop mixing as soon as it comes together.
7. Beat the egg whites: Using clean beaters, whip the egg whites on medium speed until foamy and opaque. Increase to high speed. Once the whites begin to hold shape, gradually add the remaining ¼ cup of sugar and continue beating until stiff peaks form. The whites should stand straight up without drooping when you lift the beaters.
8. Fold in the egg whites: Fold one-third of the egg white mixture into the cake batter to loosen it, then fold in the remaining whites in two additions. Use slow, deliberate strokes with the rubber spatula, scraping from the bottom of the bowl up and over. Stop the moment no white streaks remain. The finished batter should look airy and slightly thick.
9. Bake the cake: Pour the batter into the prepared pan and smooth the top evenly. Bake for 25 to 30 minutes, or until the surface is golden and a toothpick inserted in the center comes out clean.
10. Cool the cake: Let the cake cool completely in the pan on a wire rack, at least 30 minutes.

Make the Tres Leches Soak:

1. Mix the three milks: Whisk together the sweetened condensed milk, evaporated milk, and whole milk in a large bowl until fully combined.
2. Poke holes in the cake: Once the cake has cooled completely, use a fork or wooden skewer to poke holes all over the top of the cake, spacing them about one inch apart. Go all the way to the bottom of the pan. Do not be timid here.
3. Pour the milk soak: Slowly pour the entire milk mixture over the top of the cake in stages, allowing each pour to absorb before adding more. Cover the pan tightly with plastic wrap and refrigerate for at least 4 hours, or overnight for best results.

Make the Whipped Cream Topping:

1. Make the whipped cream: When ready to serve, beat the cold heavy cream in a chilled mixing bowl on medium speed until it begins to thicken. Increase to high speed, add the powdered sugar and vanilla extract, and continue beating until soft peaks form. You want lightly sweetened whipped cream that holds its shape but still looks billowy, not stiff.
2. Top and garnish the cake: Spread the whipped cream evenly over the cooled cake. Garnish with fresh strawberries or fresh berries and a dusting of ground cinnamon if desired. Serve cold.