Crush biscuits into fine crumbs. Mix with melted butter until evenly coated. Press firmly into a lined pan and chill for 20 to 30 minutes until set.
In a small bowl, mix gelatin with warm water. Let it sit for 5 minutes until it blooms and thickens.
In a large bowl, beat softened cream cheese until smooth and lump free. Add powdered sugar and mix until creamy and well combined.
Add mango puree and vanilla extract to the cream cheese mixture. Mix until smooth and evenly blended.
In a separate bowl, whip cold heavy cream until soft peaks form. The cream should be fluffy but not stiff.
Gently fold the whipped cream into the mango mixture using a spatula. Fold slowly to keep the mixture light and airy.
Warm the bloomed gelatin slightly until fully dissolved and smooth. Slowly pour it into the cheesecake mixture while stirring gently to combine evenly.
Pour the filling over the chilled crust. Spread evenly and smooth the top with a spatula. Tap the pan lightly to remove air bubbles.
Mix mango puree, sugar, and lemon juice for the topping. Stir until smooth and pour gently over the cheesecake layer.
Refrigerate for at least 6 hours or overnight until fully set.
Once set, lift from the pan, slice into bars, and serve chilled.