Preheat Oven: Set your oven to 350°F (175°C).
Prepare Pie Crust: Place the pie crust in a pie pan and set it aside.
Make the Filling: In a saucepan, mix sugar and cornstarch. Add milk and stir over medium heat until thickened.
Incorporate Eggs: In a separate bowl, beat the eggs. Gradually add a few tablespoons of the warm mixture to the eggs, stirring continuously. Then, pour the egg mixture back into the saucepan and cook for another minute.
Add Pineapple & Flavoring: Remove from heat and stir in the drained crushed pineapple, vanilla extract, and melted butter. Mix well.
Bake: Pour the mixture into the prepared pie crust and bake for about 30–35 minutes or until set.
Cool & Serve: Let the pie cool before slicing. Serve warm or chilled.
Enjoy!