Start by making the pudding.
In a medium sauce pot over medium-high heat, combine cornstarch and sugar and slowly pour in the milk, whisking as you pour. Cook for 5 minutes, whisking occasionally.
After 5 minutes turn the heat down to medium and continue cooking the mixture, still whisking occasionally, for 5 minutes or until it thickens and coats the back of a spoon. Remove from heat and whisk in vanilla extract and chopped chocolate. Let the pudding sit in the pot for 5 minutes before assembling the parfait cups.
While the pudding is cooling make the crumble layer. Melt the butter in a microwave safe bowl and set aside. Then in a food processor combine graham cracker cookies and Intense Orange chocolate squares. Pulsate until it forms a crumbly mixture (30 seconds). Pour contents into a bowl and slowly pour melted butter over the mixture. Stir until combined and a crumb mixture is formed.
To assemble the parfait cups spoon 1-2 heaping tablespoons of the crumb mixture into the bottom of 4 cups (or mason jars) so that the bottom is covered, then top with about 1/3-1/2 cup pudding, then sprinkle another spoon or two of the crumble mixture onto the pudding and spoon remaining pudding between the cups. Serve warm or cold. Store in the refrigerator.