Place the graham crackers in a blender or food processor and pulse until they are crumbs. Pour crumbs into a bowl, add sugar and melted butter, and stir well to coat crumbs.

Line a 7-inch spring-form pan with parchment paper and press the crumbs evenly into the pan. Place the pan in the freezer.

In a mixing bowl of a stand mixer, place softened cream cheese, add heavy cream and Instant Jello pudding. Blend on low until mixed.

Add sugar, powdered sugar, Vanilla extract, and lemon juice, and mix until blended. Turn the mixer on high and blend until smooth and creamy. Scrape down the sides and blend again.

In a large bowl, pour in the Lucky Charms frosted flakes cereal. Pick out 20-30 colored marshmallows and a few flakes, and place them in the cheesecake batter, gently folding them in.

Remove the pan from the freezer and pour the cheesecake into the pan over the crust, smoothing it out evenly.

Place the pan back in the freezer for at least 2 hours or overnight for best results.

To serve, remove from the freezer and the spring-form pan. Chill the vanilla frosting in the refrigerator until ready to use.

Pipe large dollops of frosting around the edge of the cheesecake and sprinkle Lucky Charms marshmallows and frosted flakes generously on top for decoration.

Cut into 2 or 3 inch wide pieces, serve, and enjoy.