In a medium mixing bowl, combine heavy cream and powdered sugar. Using an electric mixer, whip the cream until it reaches stiff peaks, then set aside.
In another mixing bowl, combine softened cream cheese, sweetened condensed milk, and lime juice. Mix until smooth, then fold in the whipped cream from earlier.
Transfer the dip to a 9-inch pie plate, then top with graham cracker crumbs and lime zest. Refrigerate until ready to enjoy!
