Prepare the Cream Mixture:

In a mixing bowl, whip the chilled heavy cream until soft peaks form. Gently fold in the sweetened condensed milk until fully combined.

Layer the Mango Float:

Spread a thin layer of the cream mixture on the bottom of a 9x13-inch baking dish. Place a layer of graham crackers on top, covering the entire surface.

Add the Mangoes:

Arrange a layer of sliced mangoes over the graham crackers. Spread another layer of the cream mixture on top of the mangoes.

Repeat Layers:

Continue layering the graham crackers, cream mixture, and mangoes until all ingredients are used, finishing with a layer of cream.

Top with Crushed Graham Crackers:

Sprinkle crushed graham crackers evenly over the top layer of cream for a decorative finish.

Chill:

Cover the dish with plastic wrap and refrigerate for at least 6 hours, or overnight, to allow the layers to set and the flavors to meld.

Serve:

Slice into squares and serve chilled for a refreshing, creamy dessert.