Preheat the oven to 350°F.
Using a rolling pin, lightly roll out the bread until it is about half the thickness. Place the bread on a cookie sheet and lightly brush the bread slices on the tops with melted butter. Toast the bread in the oven until it is lightly browned on top, about 4 minutes.
Meanwhile, place the pretzels into a zipper-top bag, seal it, and use the rolling pin to gently crush the pretzels. Break up each chocolate bar into small pieces.
Remove the bread from the oven and turn it over, so the toasted and buttered side is down. Spread the mini marshmallows evenly on 4 of the bread slices, leaving them on the baking sheet. Spread 1 ½ teaspoons of peanut butter on each of the other 4 pieces of bread, returning them to the baking sheet. Sprinkle the peanut butter coated slices with about 1 tablespoon crushed pretzels per slice. Place ¼ of the chocolate pieces over each of the pretzel coated slices.
Return the pan to the oven and bake until the marshmallows are soft, and the chocolate is melty, about 4 minutes. Place the chocolate covered slices on a cutting board. Flip each marshmallow-covered slice onto a chocolate slice. Cut each sandwich into 4 squares. Serve hot.
Recipe courtesy of Katie Workman from themom100.com.
This recipe was also part of the #SXSmores by BakeSpace.com event. Find photos and recap here.