Sift the cocoa into the sugar and cornstarch mixture in a bowl.
Pour the milk into the saucepan and sift the pudding mixture in.
Over low heat, slowly stir or whisk, letting the whisking rest every minute.
Once it reaches a custard stage (thickened but still pourable), stir in 1 capful of peppermint essence.
Continue stirring until the mixture thickens to a pudding consistency.
Once at pudding consistency, remove from the stove and let cool for 5-10 minutes.
Scoop into containers and place in the fridge to chill (1 hour).
Before serving, top with crushed candy cane and mini marshmallows.