Preheat your oven to 350°F (175°C) and line a 9x13-inch baking tray. In a large bowl, whisk together the egg yolks, sugar, salt, vanilla extract, and milk. Sift in the flour, cornstarch, and baking powder. In a separate bowl, beat the egg whites with cream of tartar until stiff peaks form. Fold the meringue into the yolk mixture, then pour into the prepared tray and bake for 15 minutes. Let it cool.
In a blender, combine mango chunks, yogurt, milk, and cardamom powder. Blend until smooth. Set aside.
In a medium bowl, whisk together sweetened condensed milk, evaporated milk, plain milk, and half of the mango lassi.
Once the cake has cooled, poke holes in the top and pour the three milk mixture over the cake, allowing it to soak. Refrigerate for several hours or overnight.
In a chilled mixing bowl, whip the heavy cream until it thickens, then fold in the remaining mango lassi.
Spread the mango whipped cream over the soaked cake and decorate with fresh mango chunks.
Slice and serve your refreshing Mango Lassi Tres Leches Cake.