Biscuit base: melt the butter in a small saucepan or a microwave. Put the biscuits into a mini food processor or ziplock bag and crush them until they resemble coarse bread crumbs.
In a bowl, combine crushed biscuits and melted butter.
Line a 23cm (9inch) springform pan with baking/parchment paper to stop the cheesecake sticking to it.Then pour the biscuit crumbs into the pan, pressing down with a back of a spoon or the bottom of a flat-bottomed tumbler to create an even layer over the base of the pan. Place the pan into the fridge to set the crust.
In a small bowl soak the gelatine in some cold water for 5-6 minutes.
Filling: peel and remove the stone from a large mango. Pulp the mango flesh and the lemon juice in a blender or use a hand blender in a large bowl. Add the coconut milk (reserving 100ml for the topping), mascarpone, sugar and vanilla to the bowl or blender and mix again to get a nice smooth mixture.
Pour about a cup's worth (250ml) of the mixture into a small pan and gently heat it, but do not let it boil. Meanwhile remove the gelatine and squeeze out any excess water from it. Once the mixture is hot, remove it from the heat and stir in the gelatine until it completely dissolves.
Add the warn gelatine mixture to the rest of the mix and blend again or simply stir well. Then remove the pan from the fridge and pour the mixture over the biscuit base.Place the pan back into the fridge for 2-3 hours until set. Topping: Once the cake has had time to cool and is set, make the topping. See notes.In a small bowl soak the gelatine in some cold water for 5-6 minutes. Gently heat the remaining 100ml of coconut milk in a small saucepan until hot but not boiling. Remove the gelatine and squeeze out any excess water from it. Once the milk is hot, remove it from the heat and stir in the gelatine until it completely dissolves.
Pour the coconut milk mixture over the top of the cake and place it back in the fridge to set for 30 minutes.
To decorate: Peel and slice the mango in half, making sure to avoid the stone in the middle. Slice each half into strips.
Then take a slice and gently fold it in half, place it around the edge of the cake. Continue to place slices around and on top of each other to make a pattern.
Alternatively, dice the mango into large cubes to decorate and add some fresh mint tips to finish.