Heat oven to 450°F. Bake pie crust as directed on box for One-Crust Baked Shell, using 9-inch glass pie plate. Cool completely on cooling rack, about 15 minutes. Reduce oven temperature to 350°F.
Meanwhile, in 2-quart saucepan, beat milk and cornstarch with whisk until dissolved. Beat in egg yolks and 3/4 cup sugar until blended. Cook over medium-low heat, stirring constantly, until mixture boils. Boil 1 minute, stirring constantly. Remove from heat. Stir in pineapple, butter and vanilla. Pour into cooled baked shell.
To make meringue topping, in medium bowl, beat egg whites with electric mixer on medium speed until soft peaks form. Slowly add 1/4 cup sugar, 1 tablespoon at a time, beating on high speed until mixture forms stiff glossy peaks. Immediately spread meringue onto hot filling, spreading to edge. Sprinkle coconut over meringue. Bake at 350°F 10 to 12 minutes or until golden brown. Refrigerate until set, about 2 hours. Cover and refrigerate any remaining pie.