Spray a 9-inch pie plate with non-stick spray and optionally line the bottom with parchment paper.

In a skillet over medium heat, melt the butter until it turns very dark brown and emits a nutty aroma, about 5 minutes.

Pour the brown butter over the graham cracker crumbs and mix well until all crumbs are evenly coated.

Press about two-thirds of the crumb mixture into the bottom and sides of the pie plate. Chill the crust in the fridge for at least 30 minutes to firm up.

Slice the mangoes and scoop out the flesh into a bowl. Mash the mangoes until chunky.

In another bowl, combine the sweetened condensed milk and cold whipping cream, then beat until firm peaks form, about 4-5 minutes.

Layer the pie starting with a layer of whipped cream mixture, followed by mango, and then crumbs. Repeat layers until ingredients run out, finishing with cream and crumbs.

Freeze the pie overnight, then let it thaw for about 30 minutes at room temperature before serving.