In a bowl, combine 2 cups coconut and butter. Press onto the bottom and up the sides of a greased 9-in. pie plate. Bake at 325° for 8-10 minutes or until golden brown. Cool on a wire rack. Toast the remaining coconut; set aside.
Drain pineapple, reserving 1/2 cup juice (discard remaining juice or refrigerate for another use); set pineapple aside. In a saucepan, combine marshmallows and reserved juice. Cook and stir over medium heat until marshmallows are melted. Remove from the heat. Add pineapple, extract and salt; mix well. Refrigerate for 2 hours or until cool.
Fold in the whipped cream; spoon into prepared crust. Sprinkle with toasted coconut. Refrigerate for 2 hours or until set. Refrigerate leftovers.