In a medium saucepan, combine half-and-half, coconut milk, eggs, sugar, cornstarch and salt. Bring to a boil over LOW heat (using a double-boiler works best), whisking constantly.
When it starts to boil a little bit and thickens up to about the consistency of a thick pudding (this takes about 15-20 minutes so BE PATIENT), remove from heat.
Stir in 3/4 cup of the toasted coconut and the coconut (or vanilla) extract. Pour into pie shell and chill for 2 to 4 hours, or until firm.
While pie is cooling, whip together topping ingredients with electric beaters.
When pie is completely cooled, top with whipped topping and sprinkle on remaining toasted coconut.
Video
Notes
Preparation time does not include the 2-4 hours of refrigeration time for the pie to set. Nutrition information is for the whole pie filling, but not the crust.