Preheat your oven to 350-360 F. Start off by preparing the sponge. In a clean bowl of your stand mixer add the eggs and egg white. Whip on a medium speed until the eggs start to froth. Then gradually add the sugar until the eggs have reached soft peaks and are fluffy and pale in color. The time varies according to egg temperature and mixer speed so keep an eye on them. Don't over whip the eggs or they will deflate.
In a small bowl sift the flour and baking powder together. Add to the egg mixture in 3 batches, folding to combime. Use a spatula to fold, and mix just until the flour combines. Then add the vanilla and butter and fold just till combined. Pour into your baking dish and bake for 25 minutes ot till the tops are golden brown and when you lightly press the center it bounces back.
While the cake is baking prepare your milk mixture. Mix the milks and mango puree and set aside. In a bowl add the topping ingredients and whip to soft peaks.
Once the sponge comes out of the oven poke small holes using a fork or knife all over the cake. Gradually pour the milk mixture all over the cake. Let the milk absorb into the sponge as it cools. Once it comes to room temperature spread over the cream topping, even it out, then cover and refridgerate for at least 5 hours, over night is best. Decorate with fresh fruit before serving.