Place a cake ring or the ring of a springform (Note1) on a plate with a flat surface. Set aside.
In a large bowl, combine all ingredients for the crust and mix until well combined. There should be no lumps or clumps. Use an electric mixer if you have one.
Pour the crumbs into prepared cake pan. Press down firmly and evenly. Place in the fridge to chill and set while preparing the filling.
Sprinkle and dissolve the gelatin powder in ⅛ cup of water in a small bowl. Let it bloom for 3-5 minutes or until it becomes gelatinous. Pulse it in the microwave for 5-10 seconds to warm it or use a water bath by putting some hot water in another bowl with the same size and place the bowl of gelatin on top of it. Mix until completely dissolved and no more granules are visible. Let it cool down to room temperature.
In a bowl, combine the cream cheese, lemon juice and sugar and whip for 3-5 minutes or until the textures become lighter and airy.
In a separate bowl, whip the whipping cream until foamy and stiff peaks forms.
Fold in the whipped cream into the cream cheese mixture until well combined. Add the dissolved gelatin and beat several times for about 10-20 seconds.
Take out the prepared crust from the fridge and pour the filling on top of it. Tap the plate several times to level out the filling and use an offset spatula to make it as even as you can. Refrigerate for 3 hours until top is set.
Run a warm knife along the inner edges of the cake ring to separate it from the cheesecake so it can be easily lifted.
Peel the mango and use a sharp knife to cut thin slices, arrange the mango slices on top of the cheesecake to form a flower or you can simply just cut cubes and spread it on top.
Sprinkle with some crushed graham and drizzle with some chocolate sauce before serving.