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.
In 2-quart saucepan, heat coconut milk, granulated sugar and milk to boiling over medium heat, stirring constantly. In small bowl, mix cornstarch and water. Reduce heat to medium-low; stir in cornstarch mixture until thickened.
In large microwavable bowl, microwave chocolate chips uncovered on Medium (50%) about 2 minutes or until melted. Stir half (about 2 cups) of the coconut milk mixture (haupia) into the melted chocolate. Spread in baked shell. Gently spread white haupia on top of chocolate layer. Refrigerate pie 2 hours.
In chilled medium bowl, beat whipping cream and powdered sugar with electric mixer on medium speed until soft peaks form. Spread whipped cream over pie; sprinkle with chocolate shavings. Cover and refrigerate any remaining pie.