In a small microwave-safe bowl, add the powdered gelatin with the water and let stand for a few minutes.
Place the bowl in the microwave and heat for 20 seconds until the gelatin is completely dissolved. Add the dissolved gelatin to the mago puree and mix with a fork until well integrated.
Place the whipping cream in a large bowl and beat with an electric mixer for about 5 minutes until it forms soft peaks.
Add the sugar and continue beating for 2 minutes until stiff peaks form.
Add the mango puree and mix with a rubber spatula in enveloping motions until smooth and homogeneous.
Divide this mixture into 4 individual dessert cups, cover with plastic wrap and refrigerate for at least 2 hours or overnight to allow the mousse to firm up a bit
Once ready, remove the mousse from the refrigerator, decorate with natural mango pieces and it's ready.