In a medium saucepan over medium heat, whisk together the sugar, cornstarch, salt, heavy cream, and milk until smooth and lump-free.

Continue cooking and stirring until the mixture begins to thicken and bubble slightly, about 5–7 minutes.

Remove the pan from heat and whisk in the egg yolks, then stir in the butter, vanilla extract, and mango puree until fully combined and silky.

Pour the mango cream filling into the prepared graham cracker crust and smooth the top with a spatula.

Refrigerate the pie for at least 4 hours, or until the filling is fully set and chilled.

Before serving, top with dollops of whipped cream, fresh mango slices and a few raspberries if desired.

Slice into wedges and enjoy chilled.