In a medium bowl, stir together the graham cracker crumbs, melted butter, and granulated sugar until well combined.

Press the crust mixture firmly into the bottom and slightly up the sides of a 9-inch pie dish or springform pan.

Chill the crust in the refrigerator while you prepare the filling.

In a food processor, puree 2 cups of chopped fresh mangoes until smooth.

In a large bowl, beat the heavy cream until stiff peaks form.

In a separate bowl, whisk together the mango puree, sweetened condensed milk, and vanilla extract.

Gently fold the whipped cream into the mango mixture until combined.

Pour the mango mousse over the chilled graham cracker crust and spread it evenly.

Chill the cake for at least 4 hours, or preferably overnight.

In a small saucepan, combine the 1 cup of chopped fresh mangoes and water. Bring to a boil over medium heat.

In a small bowl, whisk together the cornstarch with 2 tablespoons of cold water.

Reduce the heat and stir the cornstarch mixture into the mango mixture. Cook for 1-2 minutes more, or until the sauce thickens.

Pour the glaze over the chilled cake. Chill for at least an hour before serving.