Prepare a 9 by 9 inch pan by spraying with nonstick spray. Line with parchment paper, and spray if preferred.
Melt butter over medium heat in a large pot. Add marshmallows (reserving 1 cup) and stir into butter until dissolved.
Add chocolate hazelnut spread to melted marshmallows and stir to incorporate. Remove from heat.
Add pretzel sticks, Oreos, Golden Grahams, Rice Krispies, and reserved marshmallows and stir to coat evenly with chocolate marshmallow mixture. I added a bit more of each add-in to the top, just so the ingredients could be seen in my photos.
Press into the prepared pan, and sprinkle with sea salt if desired.
Allow to cool completely, and then cut into squares.