In a large baking bowl, lightly beat the whipping cream with the sugar until dissolved. Mix in the mango juice and cinnamon.
Pour the mango cream into 6 freezer-safe ramekins, cover with aluminum foil and place in the freezer for 3 hours, or preferably overnight. Gently shake the ramekins 3 times during the first hour.
To serve, dip the ramekins briefly in hot water and invert the ice cream onto dessert plates. Serve garnished with almond slivers.
Tip The whipped cream should not be whipped too hard, but only lightly until the sugar has dissolved and the mixture is smooth.