Chocolate Peppermint Pudding Cake

1. In a medium saucepan, whisk together the sugar, cocoa powder, cornstarch, and salt.
2. Slowly whisk in the milk until smooth, then whisk it all in. 
3. Place over medium heat and whisk until it just starts to bubble and becomes thick like pudding. This should take 5 to 10 minutes depending on if you have a gas or electric stovetop. 
4. Remove from heat and whisk in the vanilla, peppermint, and Nutella until smooth.
5. Pour into a large bowl and cover the surface with plastic wrap, ensuring it touches up against the pudding to prevent a skin from forming. Chill for at least 30 minutes. 
6. In the meantime, add the heavy cream to a large mixing bowl using a hand or stand mixer with the whisk attachment. Whip on high speed just until it starts to thicken slightly, about 2 minutes.
7. Scoop in the entire jar of marshmallow and continue to whip until you reach firm peaks, about 30 seconds. 
8. After those 30 minutes, the pudding should be cooled off but still slightly warm. Remove the plastic and scoop in half of the whipped cream. Fold to combine. 
9. Arrange a single layer of graham crackers in the bottom of a 9×13 dish. Pour over half of the chocolate pudding and spread evenly.
10. Arrange another layer of graham crackers on top and spread the other half of the pudding over it.
11. Lay down one more layer of graham crackers and top with the remaining whipped cream.
12. Dust with some cocoa powder and chill in the refrigerator overnight. No need to cover it.
13. Slice and serve chilled. Enjoy!