Make the funnel cakes: Whisk the pancake mix with as much water as is instructed for 2 cups of dry mix in a large bowl. Stir in the sugar and graham cracker crumbs. Rest the batter for 10 minutes.
Make the topping: Beat the heavy cream, marshmallow creme and vanilla together in a large bowl with a mixer until smooth and easy to drizzle. Refrigerate until ready to use.
Fry the funnel cakes: Add 1 inch peanut oil to a large pan with straight sides and heat the oil to 365˚ F. Line a baking sheet with paper towels. Working in batches, transfer the batter to a funnel, snipped plastic bag or squeeze bottle and carefully pour some of the batter into the pan in circling motions, overlapping a bit to create structure. (If using a funnel, control the flow by ladling the batter into the funnel and holding your finger over the tip as necessary.) Fry until golden on the bottom, about 30 seconds, then flip and cook just a bit more. Remove to the baking sheet. Repeat with the remaining batter.
Drizzle the marshmallow topping over the funnel cakes and shave the chocolate over the tops. Sprinkle with graham cracker crumbs.