Place the graham crackers in a blender or food processor, and pulse until their crumbs.  Pour crumbs in a bowl, add sugar, and melted butter, and stir well to coat crumbs.  Line a 7-inch Spring-form pan with parchment paper, and place the graham cracker crumbs in the pan. Press the crumbs evenly into the pan, smoothing the crust with the back of a spoon, and making sure the crust is even in the pan.  Place the pan in the freezer.

In the mixing bowl of a stand mixer, place the softened cream cheese, and add the heavy cream, and Instant Jello pudding.  Blend on low until all ingredients are mixed.  Add the sugar, powdered sugar, Vanilla extract, and lemon juice, and mix until blended.  Turn mixer on high, and blend until cheesecake batter is smooth and creamy.  Stop the mixer, and scrape down the sides, and blend again.  Pour the Lucky Charms frosted flakes cereal into a large bowl. Pick out the colored marshmallows, about 20 or 30, and a few flakes.  Place them in the cheesecake batter, and gently fold into the cheesecake with a spoon. Place unused cereal, back in the package, and inbox.  Place the Vanilla frosting in the refrigerator, and leave it to chill until time to decorate the cheesecake.

Remove the pan from the freezer, and pour the cheesecake into the pan, on top of the crust.  Smooth the cheesecake batter out evenly in the pan.  Place the pan back in the freezer, and allow it to sit in the freezer for at least 2 hours, or overnight for best results.

When you're ready to serve the cheesecake; remove the cheesecake from the freezer. Remove the Spring-form from the pan.  Place the vanilla frosting in a piping bag with a large star tip.  Pipe large dollops of frosting all around the edge of the cheesecake.  Sprinkle the Lucky charms marshmallows and frosted flakes, generously all over the top of the cheesecake, and dollops of frosting, making sure to place the colorful marshmallows on the frosting for a pretty presentation.

Cut into 2, or 3 inch wide pieces, serve, and Enjoy!