Combine half and half coconut milk, eggs, 3/4 cup sugar, cornstarch and salt together in a saucepan; Stirring constantly, and bring to a slow boil over low heat and cook until thick, about 30 minutes. Take the pot off the fire. Add 3/4 cup of coconut to the mixture along with the vanilla extract. Pour the coconut mixture into the baked pie crust. In a glass or metal bowl, beat the egg white until frothy. Gradually add the cream of tartar and 6 tablespoons of white sugar, and keep whisking until soft peaks form. Spread the egg white mixture over the pie. Sprinkle half a cup of coconut over the pie. Bake at 350 for 12 to 15 minutes.
