Preheat your oven to 350°F. Lightly grease and flour a 9x13-inch baking dish.
In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
In a large mixing bowl, beat the egg yolks with half of the sugar (about ½ cup) until pale and thick, about 4 minutes using an electric mixer on medium-high speed.
Beat in the melted butter and milk until fully combined. Gently fold in the flour mixture until just incorporated — don't overmix at this stage.
In a separate clean bowl, whip the egg whites with the remaining sugar (about ½ cup) until stiff peaks form when you lift the beaters.
Fold one-third of the whipped egg whites into the yolk batter to lighten it. Then gently fold in the remaining whites until no white streaks remain.
Pour the batter into your prepared pan and bake for 25-30 minutes, or until the top is golden and a toothpick inserted in the center comes out clean.
While the cake cools for about 10 minutes, make the milk soak: whisk together the condensed milk, evaporated milk, heavy cream, and vanilla.
Pierce the warm cake all over with a fork or skewer — this is crucial. Slowly pour the milk mixture evenly over the cake, letting it sink into those holes you've made.
For the mango topping: pulse about 2 cups of diced mango in a food processor until smooth. Reserve the remaining fresh mango for garnish.
In a chilled bowl, whip the heavy cream with powdered sugar and lime juice until soft peaks form (it should hold its shape but still be silky).
Gently fold in the processed mango until just combined — don't overmix or you'll lose all that lovely texture.
Spread the mango cream evenly over the soaked cake. Chill for at least 2 hours before serving so everything sets properly.
