In a large microwave-safe bowl, place semisweet chocolate, butterscotch chips, and butter and gently stir. Melt mixture in 20-second increments, stirring every 15 seconds until fully melted and smooth when stirred.
Add mini marshmallows and walnuts into the chocolate mixture and stir to coat. Using a tablespoon, drop 1 inch-sized spoonfuls onto a wax or parchment paper lined baking sheet.
Place in the refrigerator to cool and set for about 10 minutes to set
Notes
Crock Pot Instructions: Spread out the walnuts on the bottom of the slow cooker. Then top with chocolate chips, butterscotch, and butter. Cover and cook on low until the chocolate is melted (about 1 hour). Then stir together with the marshmallows. Drop 1-inch sized scoops onto parchment paper and cool.
You can keep leftovers in an airtight container the freezer or refrigerator, but they should be kept cool to prevent melting.
To make on the stovetop: Place a glass bowl on top to create a double boiler. Add your chocolate, butter, and butterscotch chips to the bowl. Continually stir until they are melted and smooth.