Marshmallow topped Reeses cups are an option, but what else is there?
Am dirty American, for geographical purposes.
Try making this and throw some chocolate chips on top? https://www.allrecipes.com/recipe/9462/peanut-butter-marshmallow-squares/
Sky Bars
If you like marshmallow and chocolate together, try bubulubu.
Learn to cook
Never seen that combo as a candy bar, but I’ve absolutely made chocolate chip fluffernutters before