In a medium bowl, combine graham cracker crumbs and granulated sugar. Stir in melted butter until crumbs are moistened. Press mixture evenly into the bottom of a 9×13 inch baking dish.
In a large bowl, beat softened cream cheese until smooth. Beat in powdered sugar and vanilla extract until well combined. Gently fold in thawed whipped topping. Spread this mixture evenly over the crust.
In a separate bowl, whisk together instant chocolate pudding mix and milk until thickened, about 2 minutes. Spread the pudding mixture over the cream cheese layer.
In a microwave-safe bowl, combine milk chocolate chips and heavy cream. Microwave in 30-second intervals, stirring between each, until smooth and melted. Pour the chocolate ganache evenly over the pudding layer.
Cover the dish and refrigerate for at least 4 hours, or until firm.
Cut into bars and serve chilled.
Notes
For an Oreo crust, use 2 cups of finely crushed Oreo cookies (filling removed) instead of graham crackers.
These bars can be made up to 2 days in advance and stored in the refrigerator.
Ensure your cream cheese is fully softened for a smooth, lump-free layer.