Prepare by buttering a 9" x 13" pan and chopping up dark chocolate Reese's peanut butter cups into quarters until you have 1 cup. Set aside. (If you can't find dark chocolate Reese's, feel free to use the original ones, I won't tell.)
Then, begin by melting 6 tablespoons of butter over low heat in a large pot and adding 2 packages of marshmallows (10.5 oz bags) to the melted butter. Stir until all of the marshmallows are melted.
Stir in up to 1 cup of dark chocolate peanut butter (again, if you can't find dark chocolate, regular will do), 1-1/2 teaspoons of vanilla extract, and 1/4 teaspoon of salt. Mix well. Add in 8 cups of Rice Krispies, about one cup at a time, and stir until they are evenly coated.
Remove the pot from the heat and stir in your chopped up dark chocolate Reese's peanut butter cups and one cup of dark chocolate chips (and if you can't find dark chocolate... you guessed it... use regular). Mix until pieces of chocolate are scattered throughout the mixture but don't over mix so that the pieces are all melted. Now dump your ooey gooey mixture into your 9 x 13 pan. Spread as evenly as possible, continually pressing on the surface until it is flat.
If you are not decorating your Rice Krispie Treats, simply let them sit for about an hour before indulging. You may have to stand guard with your wooden spoon to fight off hungry hubbies and kiddos!