Preheat oven to 350 degrees F. Line 2 muffin tins with 24 paper liners. Set aside.
In a medium bowl, beat together the cream cheese, egg and powdered sugar until blended and thick, about 1 minute. This is your cheesecake filling. Set it aside.
In a large bowl, prepare cake mix according to package instructions. Stir in cheesecake pudding mix until blended. Portion batter evenly into muffin tins, about 2/3 full. Add one heaping Tablespoon of cheesecake filling and spoon it on top of the batter. Bake cupcakes for about 15-18 minutes or until a toothpick inserted around the edge of the cupcake comes out clean or with moist crumbs. Allow to cool completely.
In the bowl of a stand mixer, cream together the butter, cream cheese and vanilla with the paddle attachment until creamy and light, about 2 minutes. Gradually add in the powdered sugar, about a cup at a time, until frosting is light and fluffy.
Pipe the frosting onto the cooled cupcakes, taking care to cover the cheesecake middles of the cakes. Garnish with graham cracker crumbs. Serve! Store leftovers in the fridge, covered.