Line two baking sheets with parchment paper. Carefully break apart the graham crackers along the lines where they are scored, yielding 4 rectangles from each cracker. Lay half of them out with some space between them on them on the parchment lined baking sheets.
Scrape the peanut butter and fluff into two disposable pastry bags fitted with large plain tips or into 2 gallon sized zipper top bags (which are then zipped shut.) If using the zipper top bags, squeeze the fillings toward one corner, twist the bag to prevent it from squirting back into the empty space, use a twist tie to hold it in place and snip the corner off. Pipe a line of peanut butter down each cracker. Follow this by squeezing a dollop of marshmallow creme about the size of a marble or a nickel into the center of each line of peanut butter. Top each of these with one more graham cracker square. Set aside while preparing the chocolate coating.
Combine the chocolate chips or chunks and coconut oil or shortening in a microwave safe bowl. Microwave on HIGH for 2 minutes. Stir well, return to the microwave, and heat on HIGH in 30 second bursts, stirring after each burst, until the chocolate is fully melted and the mixture is smooth.
Pick up one graham cracker/peanut butter/marshmallow sandwich at a time, lower it into the melted chocolate, turn over to coat completely, and use two forks to lift it, allowing the excess chocolate to drain away as completely as possible before transferring back to the parchment lined sheet. Repeat with remaining graham sandwiches. Sprinkle the tops with micro Mallow bits, if desired, and allow the chocolate to set up. These are good stored at room temperature for up to 2 weeks.