1Melt the butter over low heat.
2Put the gelatin in cold water to soften it.
3In a food processor bowl, mix the speculoos and melted butter into a thick paste.
4Pour this mixture into a 20 x 20 centimeter square frame placed on a baking sheet lined with parchment paper.
5Tap with the back of a spoon, and smooth the bottom with a spatula. Keep cool.
6Whip up the liquid cream until stiff. Set aside.
7In a bowl, whisk the sugar and eggs with an electric whisk to get a frothy mixture. Grate the lemon zest, and scrape the vanilla seeds.
8Add them to the the egg and sugar mixture, and then add the Brillat Savarin cheese.
9Whisk on medium speed.
10Squeeze the lemon juice, and heat in a small saucepan.
11Squeeze the gelatin, and let it melt in the pan.
12Add to Brillat Savarin and beat at high speed.
13Using a spatula, stir gently the whisked cream into this mixture . When the mixture is well blended, pour it over the speculoos base.
14Leave a 5 millimeter space at the top of the frame for the icing.
15Refrigerate for at least 2 hours.
16Mango Passion Fruit Icing Preparation:
17Soften the gelatin in cold water. Heat 1/3 of the juice in a saucepan. Squeeze the gelatin, and let it melt in the pan.
18Add the remaining juice.
19Remove from heat, let cool down to warm, and pour this mixture over the cheesecake (it should not be too hot so as not to spoil the cream).
20Let cool for at least 30 minutes before serving.
21Mango Puree Preparation:
22Peel the mango, cut it into chunks, and mix them in a blender with the sugar and lime juice. Set aside in the refrigerator.
23Using a sharp knife, carefully unmold the cheesecake.
24To cut the cake, run your knife under hot water each time for a cleaner cut.
25To serve, place a piece of cheesecake on each plate, and a little bit of mango puree.