Line a loaf pan with parchment paper and set aside.
Add the chocolate chips and butter to a large heat-safe bowl. Warm the chocolate in the microwave in 30 second increments, stirring in between each, until both are melted and well-combined. Alternatively, melt the chocolate and butter using a double boiler.
Set aside to cool to room temperature—you don’t want to melt your marshmallows.
To the cooled chocolate, stir in the cookie bits, marshmallows, and dried cherries.
Press the mixture into the parchment-lined pan, then set in the fridge to chill for at least 2 hours.
Once the bar is chilled, slice into pieces (we like bread-like slices or squares). Store in the fridge in a tightly-sealed container for up to two weeks.