Line a baking sheet with parchment or wax paper and spray a small (1 TBSP) cookie scoop with nonstick cooking spray.
Place 20 level scoops of marshmallow creme on the prepared baking sheet and freeze while you prepare the rest of your ingredients and dough.
Break or chop one of the three chocolate bars into 20 squares and set aside.
Roughly chop the remaining two milk chocolate bars and set aside.
Line three baking sheets with parchment paper. Set aside.
Combine flour, the 1/4 cup of fine graham cracker crumbs, baking soda and salt. Set aside.
Cream together butter and both sugars.
Add eggs, one at a time, to the butter and sugar and mix until just combined.
Add vanilla to the wet ingredients and mix until just combined.
Add dry ingredients to wet. In 3 batches or all at once if using large stand mixer.
If using a stand mixer, remove bowl and add the two roughly chopped chocolate bars and the 1 1/2 cups of coarse graham cracker crumbs and pieces. Mix with a wooden spoon or sturdy spatula.
Preheat oven to 350℉ ****see note
Set up an assembly line with your cookie dough, prepared baking trays, marshmallow creme and chocolate squares.
Spray a large (2 TBSP/1 ounce) cookie scoop with nonstick cooking spray.
Place a slightly overfilled scoop of cookie dough in your hand and flatten.
Place a scoop of marshmallow creme in the center and wrap the dough around (it's okay if some marshmallow creme isn't covered)
Place up to 8 cookies per baking tray.
Add one chocolate square to the top of each cookie dough ball
Refrigerate cookie sheets for 30 minutes *****see note
Bake for 16 minutes until edges of the bottom of the cookies are just starting to brown. Rotate and swap trays halfway through bake time.
Let cool completely on trays on cooling racks.