Preheat the oven to 170 degrees C. Melt the butter in a heavy-bottomed pan over moderate heat and mix in the sugar. Once the sugar has dissolved and the mixture is gently bubbling, add the lime zest and juice and simmer on low heat for a couple of minutes till very lightly thickened. Set aside to cool.

In a bowl whisk together the flour, baking powder and salt.

In another, larger bowl, cream the butter and sugar on high speed till light and fluffy. One by one, add the whole egg and separated yolks.

Mix in the vanilla and half the flour followed by the mango pulp and finally the rest of the flour.

In a clean bowl, whisk the egg whites until stiff and gently fold into the cake batter.

Arrange the mango slices in a circle over the syrup so that the slices overlap each other.

Pour the batter gently to evenly cover them and bake for 40-50 minutes till you get a clean toothpick.

Rest the pan for 10 minutes outside the oven and lightly run a knife (if needed) to loosen the edges of the cake before unmolding on a plate.