Add 3 Tbsp. graham cracker crumbs and 1 Tbsp butter to each mason jar. Microwave 30 seconds or until butter is melted; stir and press down to form the crust.
Top crust with 3 Tbsp. Nutella and 1 Tbsp. mini chocolate chips.
In a separate bowl, mix cream cheese, marshmallow fluff, and vanilla extract with a hand mixer 2 minutes. Divide evenly into mason jars, approx. 1/3 cup in each.
Top each jar with 1/2 graham cracker, broken in pieces, and leftover chocolate chips.