Heat oven to 450°F. Bake pie crust as directed on box for One-Crust Baked Shell, using 10-inch tart pan with removable bottom or 9-inch glass pie plate. Cool completely on cooling rack, about 15 minutes.
In small bowl, microwave 1 oz chocolate and the oil uncovered on High 20 to 30 seconds, stirring every 10 seconds, until melted. Spread in bottom of crust.
In 1-quart saucepan, mix granulated sugar and corn syrup; cook over medium heat 4 to 6 minutes (do not stir). Stir in butter, 1/3 cup whipping cream and 1 cup macadamia nuts. Cook 4 to 5 minutes, stirring frequently, until hot. Carefully spread in crust. Freeze until set, about 20 minutes.
Meanwhile in large bowl, beat 1 cup powdered sugar, the cream cheese and vanilla with electric mixer on high speed until smooth. Add melted chocolate; beat until smooth. Gradually add 1 1/2 cups whipping cream, beating until soft peaks form. Spread chocolate filling over nut filling. Refrigerate until filling is set, 2 to 3 hours.
In medium bowl, beat topping ingredients with electric mixer on high speed until stiff peaks form. Spoon over chocolate filling. Top with toasted macadamia nuts.