Preheat oven to 325°. Using the butter wrapper, grease a 9"x13"x2" glass baking dish. Sprinkle pan lightly with flour to coat, set aside. Crush graham crackers by placing in a paper lunch bag, 8-10 at a time, and roll with a rolling pin until crumbled. Pour into a bowl, then repeat. The whole batch will take about ten minutes. Separate the egg yolks from the egg whites (reserve the egg white for another recipe). With a mixer, cream the butter and sugar on high speed until well-blended. Reduce speed to low, add egg yolks, PURE VANILLA EXTRACT and KORINTJE CINNAMON, blend well to combine. Sprinkle flour and baking powder into bowl with graham cracker crumbs. With mixer on low speed, alternate adding graham crackers and milk in thirds. Start with graham crackers, end with milk. The batter is fairly dry, so make sure it is well mixed. If you're using nuts, add them at this point by hand, stirring gently into the batter. Spoon the batter into the pan, smoothing toward the edges. Bake in a preheated 325° oven for 40-45 minutes. The cake will pull away from the edges of the pan when it is done, and the middle will be springy to the touch. Remove from oven, let cool completely, then dust with powdered sugar or frost and cut into serving squares. To prepare frosting, let cream cheese and butter come to room temperature. Blend thoroughly with PURE VANILLA EXTRACT, then beat in the powdered sugar at low speed. Spread smoothly over cake.