In a large saucepan, melt the chocolate chips and butter over low heat, stirring until smooth.

Remove from heat and let the mixture cool slightly so the marshmallows don’t melt when added.

Stir in the miniature marshmallows and toasted walnuts until evenly coated.

Divide the mixture into three equal portions and place each on a sheet of waxed paper. Use the paper to shape each portion into a 10-inch-long roll.

Spread the flaked coconut out and roll each log in it until fully coated.

Wrap each roll tightly in waxed paper and refrigerate for at least 4 hours, or until firm.

Slice crosswise into ½-inch pieces and serve chilled or at room temperature.