01 -
In a large bowl, whip the cold heavy cream with an electric mixer until soft peaks form.
02 -
Gradually add the sweetened condensed milk and continue whipping until stiff peaks form and the mixture is smooth and airy.
03 -
Arrange a single layer of graham crackers at the bottom of a 9x13-inch (23x33 cm) baking dish, breaking crackers as necessary to cover gaps.
04 -
Spread a third of the whipped cream mixture evenly over the graham crackers.
05 -
Top with a layer of sliced mangoes, covering the cream completely.
06 -
Repeat the layers (crackers, cream, mango) two more times, finishing with a layer of mangoes on top.
07 -
Cover the dish with plastic wrap and refrigerate for at least 6 hours, preferably overnight, to allow the crackers to soften and flavors to meld.
08 -
Slice and serve chilled.