Preheat your oven to 375°F (190°C). Blind bake the pie crust until golden, about 12 minutes. Let cool completely.

While crust bakes, toast 1 cup of flaked coconut on a baking sheet for 5–7 minutes, stirring halfway, until golden brown. Set aside.

In a medium saucepan, whisk together sugar, cornstarch, and salt. Gradually whisk in milk until smooth.

Cook over medium heat, stirring constantly, until mixture thickens and bubbles, about 5 minutes.

Temper egg yolks by adding a small amount of hot custard into yolks, whisking quickly. Return tempered yolks to saucepan and cook 1 more minute.

Remove from heat. Stir in butter, vanilla, and 1 cup toasted coconut. Pour filling into the cooled crust.

Cover pie surface with plastic wrap. Chill in refrigerator at least 4 hours (or overnight) until fully set.

Before serving, whip heavy cream, powdered sugar, and vanilla until stiff peaks form. Spread whipped cream over pie and sprinkle with extra toasted coconut.