Make the Chocolate Pudding:
In a medium saucepan, whisk together milk, sugar, cocoa powder, cornstarch, and salt until smooth.
Cook over medium heat, stirring constantly, until the mixture thickens and begins to bubble.
Remove from heat and stir in vanilla extract and chocolate chips until melted and smooth.
Transfer the pudding to a bowl, cover with plastic wrap (pressing it directly onto the surface to prevent a skin from forming), and refrigerate for at least 2 hours or until chilled.
Prepare the Baileys Whipped Cream:
In a mixing bowl, combine heavy cream, Baileys Irish Cream, and powdered sugar.
Using an electric mixer, beat until soft peaks form. Be careful not to overwhip.
Assemble the Parfaits:
Spoon a layer of chocolate pudding into the bottom of each parfait glass or dessert cup.
Add a layer of Baileys whipped cream, then sprinkle a layer of crushed mint chocolate candies.
Repeat the layers until the glasses are full, finishing with whipped cream and a generous sprinkle of mint chocolates or chocolate shavings.
Chill and Serve:
Refrigerate the parfaits for at least 30 minutes before serving to allow the flavors to meld. Serve chilled.