Sprinkle the gelatin over the cold water and let it bloom for 5 minutes.
Microwave the gelatin in two 15-second intervals, stirring until completely dissolved. Allow it to cool slightly.
Blend the mango flesh into a smooth puree.
Reserve ¾ cup of the puree for the jelly topping.
Add the remaining mango puree, cream cheese, whipping cream, sugar, and dissolved gelatin to a food processor.
Blend until smooth and creamy.
Pour the filling over the chilled biscuit base.
Refrigerate for at least 3 hours until the surface is firm.