- Preheat the oven to 180° C (350 °F). Butter a 20-cm (8-inch) springform pan.
- In a bowl, beat the eggs, sugar and vanilla with an electric mixer for 4 to 5 minutes. Gently fold in the flour alternately with the melted butter. Spread into the pan. Bake in the middle of the oven until a toothpick inserted in the centre of the cake comes out clean, about 20 minutes. Cool completely in the pan.
- In a bowl, sprinkle the gelatin over the water. Let bloom for 5 minutes. Melt the gelatin for a few seconds in the microwave oven and whisk in the mango purée. Refrigerate for 15 minutes.
- In a bowl, beat the egg whites until frothy. Add the sugar and continue beating until stiff peaks form.
- Gently fold the whipped cream into the mango purée. Fold in the egg whites.
- Pour the mousse over the cake and refrigerate for at least 4 hours.
- Do not unmould.
- In a bowl, sprinkle the gelatin over the water. Let bloom for 5 minutes. Melt for a few seconds in the microwave oven. Add the gelatin into the juices. Stir to blend. Let cool. Pour the juice over the surface of the cake and refrigerate for 2 hours.
- Run a knife around cake before removing the hinge.