Preheat your Traeger Grill to 350* and close the lid.
While the grill preheats, prepare the dip inside.
In a 12" cast iron pan, break apart 2 tbsp of softened butter and spread around the pan.
To the butter in the pan, add half of each of the chocolate chips and the other chips.
Use a spoon to stir the mixture to combine.
Add the remaining chips and stir to distribute, then spread it out evenly in the pan.
Top the chocolate mixture with marshmallows.
If using two kinds of marshmallows, alternate them on top so that they melt more evenly.
Place the prepared pan in the hot Traeger and close the lid
Allow to cook for about 15 minutes, checking regularly. The marshmallows will puff up in the heat and may drip over the sides of the pan.
Cook until the marshmallows are toasted, and toast extra with a blow torch at the end if desired.
Carefully transfer the hot pan indoors and serve the s'mores dip with a variety of tasty edible dipping utensils.