Combine whipping cream, mango nectar, and passionfruit nectar in a bowl. into mixing bowl. Add sugar and beat on high until stiff peaks form. (A chilled mixing bowl will help speed up the process, it could take 3-4 minutes) Chill in fridge until ready to use.
Add all slush ingredients to a blender, cover, and pulse until a slushy texture is achieved. Pour into glasses and top with prepared foam topping. Enjoy!