Preheat the oven to 325 degrees and line a cupcake pan with cupcake liners.
In a large mixing bowl, combine the cake mix, instant pudding, eggs, water, and canola oil with a stand or hand mixer.
Add in chocolate chips and mix well.
Using a 3 tablespoon cookie scoop or spoon, fill cupcake liners about 3/4 of the way full with the chocolate batter.
Bake for 30 minutes.
Remove the cupcakes from the oven and put a large marshmallow in the center of each cupcake and twist a little to push them into the cupcake.
Put the cupcakes back into the oven for 2 minutes to let the marshmallows melt.
Remove the cupcakes from the oven and press the marshmallow down (this will help the marshmallow melt on the inside of the cupcake and fill in the extra space around the cupcake).
Let cool for 10 minutes in the cupcake pan before transferring to a cooling rack.
While the cupcakes are cooling, make the frosting by combining the powdered sugar, unsweetened cocoa powder, water, and vanilla extract and mix until smooth.
Fill the marshmallow indention with mini chocolate chips and then cover the chocolate chips with frosting.
Cut large marshmallows in half and put half of a marshmallow on each cupcake and drizzle with frosting.
Garnish with Peppermint Crunch or Holiday Sprinkles.
Cut holiday straws in thirds and insert them into the cupcakes.
Let cupcakes cool completely and enjoy!