Preheat the oven to 350F.
Using a mixer, mix the butter, sugars, peanut butter, eggs and vanilla together until combined.
Add in the flour, soda, and salt in and mix until just combined.
Fold in chocolate chips, peanut butter chips, peanut butter cups and marshmallows.
Using an ice cream scoop, scoop the dough onto parchment on cookie sheets. (6 per sheet, these will be large, jumbo cookies!) You can roll these into balls if you wish as well.
Use your hand and slightly flatten each scoop of dough.
Cook for 10-12 minutes at 350. If your dough is chilled, allow a few more minutes for baking.
Remove cookies from oven and cool on baking sheet 5-10 minutes before placing on cooling rack. If you try to remove them right after baking they will fall apart, so you need to wait for them to set up.
Makes 18 large cookies