Place graham cracker crumbs, shredded coconut and granulated sugar in a medium-sized bowl. Stir to combine.
Add melted butter to bowl and toss mixture until butter is evenly distributed.
Gently press graham cracker mixture on the bottom and sides of the pan.
Bake crust for 12 minutes. Cool completely before using.
Mango Pastry Cream
Place cornstarch in a medium-sized bowl. Add ½ cup of the milk (measure #1) and whisk until cornstarch is dissolved.
Add the egg and egg yolks to the cornstarch/milk mixture. Whisk lightly until combined.
Combine remaining milk (measure #2), mango puree and granulated sugar in a medium-sized saucepan. Heat over medium heat until the mixture reaches a low boil. Remove from heat.
Slowly pour 1 cup of the hot mixture into the egg mixture; whisking constantly.
Return the remaining milk/mango/sugar mixture to a simmer over medium-low heat. Slowly pour the egg mixture into the saucepan, whisking constantly.
Continue to whisk vigorously until the mixture is quite thick (3 - 5 minutes). The continuous whisking is important in this step. The eggs will curdle if not whisked properly - which results in a lumpy, eggy pastry cream. Note: the mixture is thick enough when the cream forms ribbons and becomes difficult to whisk.
Remove from heat. Add the butter and whisk until all the butter is melted.
Pour the mixture into the prebaked graham cracker crust. Place plastic wrap over the filling to prevent a crust from forming. Refrigerate for 2 hours or until set.
Mango Glaze (optional)
Sprinkle powdered gelatin over the cold water. Allow the gelatin to set (approximately 5 minutes).
Gently melt the gelatin in the microwave or over the stovetop. Allow to cool slightly (1 - 2 minutes).
Add the melted gelatin to the mango puree. Stir well.
Pour the mango glaze over the pastry cream in the tart shell. Place tart in refrigerator and allow to set completely (1 - 2 hours).
Video
Notes
If making your own graham cracker crumbs in a food processor, you will need approximately 16 graham crackers to make 2 cups of crumbs.The pastry cream must be well thickened for this recipe to work. The mixture is thick enough when the cream forms ribbons and becomes difficult to whisk. At this point, immediately remove saucepan from heat.