Preheat your oven to 325°F (160°C). Pulse graham cracker sheets, confectioners' sugar, and toasted shredded coconut in a food processor until finely ground. Transfer to a bowl, add melted butter, and combine until resembling wet sand. Press into a 9-inch pie pan and bake for 12-15 minutes until slightly golden. Allow cooling.

In a mixing bowl, beat the egg yolks using an electric mixer on medium speed for about 4 minutes until thick and pale. Gradually stir in sweetened condensed milk, pure mango puree, and lime juice until smooth. Pour the filling into the cooled crust and smooth it out.

Bake the pie in the preheated oven for around 30 minutes. The filling should be set with a slight jiggle in the center. Remove and allow to cool to room temperature before chilling.

Transfer the pie to the refrigerator to chill for at least 1 hour. Prepare for the meringue topping while the pie cools.

For the meringue, whisk the egg whites, granulated sugar, and a pinch of salt in a heatproof bowl over simmering water. Stir until sugar dissolves. Remove from heat and whip until glossy and firm peaks form, about 10-12 minutes.

Dollop or pipe the whipped meringue over the chilled pie. Preheat the broiler and place the pie under it for 2-3 minutes until the meringue is lightly toasted. Watch closely to prevent burning.

Sprinkle additional toasted coconut on the meringue for garnish. Slice and serve chilled.