In a large mixing bowl, pour in the cold heavy whipping cream. Using an electric mixer, beat the cream on medium speed until soft peaks form, which will take about 3-5 minutes.

Gradually pour in the sweetened condensed milk while continuing to whip the mixture until you achieve stiff peaks, taking another 2-4 minutes.

Lay down a single layer of graham crackers at the bottom of a 9x13-inch baking dish.

Spread a third of the whipped cream mixture evenly over the layer of graham crackers.

Slice ripe mangoes into thin pieces and layer them generously over the whipped cream.

Repeat layering with another layer of graham crackers, followed by another third of the whipped cream, and then another layer of sliced mangoes.

End with a final layer of mango slices on top for a gorgeous finish.

Cover the baking dish tightly with plastic wrap and chill in the refrigerator for at least 6 hours, ideally overnight.

Slice your Mango Float into squares and serve chilled.