Prepare the crust if you haven’t done so and have it ready to be filled.In a big, microwave-safe bowl, combine the cream of coconut, milk and marshmallows. Stir it all together, coating the mallows with the cream of coconut mixture. Microwave on high, stirring every 30 seconds, until the marshmallows are melted and the mixture is smooth.
Put the whole bowl in the refrigerator for 1 hour to thicken.After 1 hour, whip all the cream and set it aside. With a hand-held or stand mixer, beat the now-slightly-thicker coconut mixture for about a minute or until it’s lightened (it won’t be fluffy at this point). Fold in all the whipping cream, then fold in just 1 cup of the coconut. Pile it all in the pie crust and chill for 2-3 hours. In the meantime, toast the remaining coconut by laying it on a parchment or foil lined cookie sheet and baking at 350 for about 8 minutes.
