Mix cornstarch, sugar, and salt in a medium-size saucepan. Add milk and cream and cook over medium heat until thickened, stirring constantly. Pour a spoonful amount of hot mixture into egg yolks; blend thoroughly. Add about 1/3 of the milk mixture to the egg yolks, then pour back into the saucepan. Cook another 2 or 3 minutes. Remove from the heat and add the butter and vanilla. Stir in 1/2 cup of the coconut. Cover with plastic wrap and press plastic against the custard. Refrigerate until completely chilled.

When ready to serve, make the topping by pouring whipping cream into a medium-size mixing bowl. Add confectioner's sugar and vanilla. Beat until stiff peaks form. Remove pie from refrigerator and remove plastic wrap. Spread whipped cream over the custard and sprinkle with the remaining 1/2 coconut.

Serves 8-10 depending on how large you slice the pie.