First, make the base of the cheesecake. Pulse the lucky charms cereal in a food processor until finely ground. Add the melted butter, then press them into the bottom of three 4-inch spring form pans. Place these in the fridge while you make the filling.
To make the filling, place the cream cheese in a bowl and beat with an electric mixer until smooth. Add the whipping cream, lemon juice, vanilla extract and sugar and mix until smooth. Mix together the gelatin and water in a small bowl and microwave for 30 seconds. Add the gelatin to the filling, and mix together with an electric mixer until fully combined. Divide the mixture into 3 bowls and dye them pink, yellow and blue.
Divide the pink filling between the pans and smooth the surface. Sprinkle some lucky charms marshmallows on top and gently press down with a knife. Place in the freezer for 15 minutes, or until the surface is firm. Repeat with the yellow layer, adding some more marshmallows. Freeze for 15 minutes. Smooth the blue layer on top and place the cheesecakes into the fridge (not freezer) for 2-3 hours, or overnight.
Carefully remove the cakes from the spring form pan by running a sharp knife around the edges of the cake, then release the sides of the pan and carefully slide off the cake.
Dollop some whipped cream on top and decorate with lucky charms marshmallows. Enjoy!