Instructions

1. Preheat the oven to 350F. Butter a 9-x-13 baking pan.
2. In a medium bowl, whisk together the flour, 1/2 cup of the sugar, baking powder and salt. Set aside. In a large bowl, whisk together the egg yolks, butter, milk and vanilla extract until smooth and well combined.
3. With an electric mixer, beat the egg whites on medium speed until they are frothy and thick, but before peaks have begun to form. Slowly add in the remaining 1/4 cup of sugar, a little at a time, while beating the egg whites. Continue to beat until the whites have become glossy and firm peaks form.
4. Whisk half of the flour mixture into the egg yolks, until the batter takes on a paste-like consistency. Whisk in a quarter of the egg whites to lighten the mixture.
5. Fold in another quarter of the egg whites into the batter, using a rubber spatula. Sift in half of the remaining flour mixture and fold in. Fold in another quarter of the egg whites, then the remaining flour, and then the remaining egg whites.
6. Pour the batter into the prepared baking pan and smooth the top with a spatula. Bake until the cake is golden and a toothpick inserted into the center comes out clean, 20-25 minutes. Cool.
7. Once the cake is cooled, poke holes into it using a toothpick or the tines of a fork. Cut the cake into 24 slices, but do not remove from the pan.
8. Make the milk mixture: In a small saucepan, combine the three milks with the sauce and heat until the milk is steaming. Pour the milk mixture over the cake (which has already been cut into pieces). Cover with plastic wrap and chill for at least one hour, or preferably overnight.
9. In a blender or food processor, puree the mango. Add sugar by the tablespoon if necessary, based on how sweet the mangoes are.
10. Just before serving, whip the heavy cream with half of the mango puree (remember to chill your beaters and metal bowl in the freezer beforehand). Add sugar by the tablespoon if you deem the whipped cream to not be sweet enough. Beat until the whipped cream holds semi-firm peaks.
11. Spread the mango whipped cream over the cake using a knife or spatula. Dollop on the remaining mango puree, then use a knife to cut swirls into a marbled pattern. Serve, along with any remaining mango puree on the side.