In a mixing bowl, combine the drained crushed pineapple with sweetened condensed milk
Pour the pineapple filling into the prepared graham cracker crust.
Add dollops of thawed cool whip or whipped topping on the pineapple mixture and spread evenly.
Cover the whipped cream with unsweetened coconut flakes and refrigerate the pie for a few hours or until it sets completely.
Garnish with cherries or pineapple chunks before serving.