In a medium saucepan, melt ½ cup of unsalted butter on low heat.
Once butter is almost melted, add 12 ounces semi-sweet chocolate chips to pan. Use a spatula or wooden spoon to combine butter and chocolate. Stir occasionally to ensure chocolate does not burn.
Remove pan from heat and allow to cool enough to place your finger in the melted chocolate, but chocolate has not solidified.
Stir in mini marshmallows until completed coated in chocolate.
Separate chocolate mixture onto two sheets of wax paper.
Use wax paper to form the mixture into a log shape. Pro tip: you can also use the wax paper box to help form the log's shape.
Place logs on baking sheet and refrigerate for 8 hours.
Remove from fridge and use a sharp knife to slice logs into ½ inch to 1 inch thick slices.
Serve immediately or put back in fridge until serving.
Video
Notes
If your chocolate solidifies, just put it back on low heat until it melts again and then let cool once again.