Put the speculoos in the bowl of a blender, add the melted butter and mix a few seconds. Pour into a rectangular baking dish and press with the bottom of a glass. Reserve 20 minutes in the refrigerator.
Meanwhile, preheat the oven to 160 ° C (5/6). Soak the gelatin in a bowl of cold water.
In a bowl, whip the Philadelphia with the powdered sugar to obtain a smooth preparation. Stir in liquid vanilla extract, then eggs and yolks one by one. Heat the milk, dissolve the drained gelatin, then add to the mixture.
Finally add the cream. Pour this mixture over the biscuit bottom and bake. After 15 minutes of cooking, lower the oven temperature to 120 ° C (tea 4) and cook another 50 minutes.
Let cool in the oven off, then reserve in the refrigerator for at least 12 hours (ideally 24 hours). Cut into pieces and coat with a cordon of lemon curd before serving.