Spray 9x13” pan or baking dish with cooking spray.
Pour chocolate pudding into a large mixing bowl.
Add one cup half-and-half and mix well on low speed of electric mixer.
Continue adding cream in ½ cup measures, mixing well after each addition continuing on low speed of electric mixer.
Once all the cream has been added, adjust mixer to high speed and mix for about two minutes until mixture has thickened.
Add Cool Whip and stir well to combine.
Take one package of the graham crackers and spread over bottom of baking dish.
Cover with half of the chocolate pudding mixture.
Spread with another layer of graham crackers, followed by the remaining chocolate pudding mixture.
Top with the last layer of graham crackers.
Spread chocolate frosting over all.
Chop Snickers bars and sprinkle over top of the icing.
Gently press the chopped Snickers bars into the icing with your fingertips.
If desired, decorate the top with maraschino cherries.
Refrigerate a few hours or overnight before serving.