Melt the Chocolate: In a microwave-safe bowl, combine about 1 cup of white chocolate and 1 tablespoon of vegetable shortening. Heat in 30-second intervals at medium power, stirring after each interval until smooth. This will serve as the adhesive.

Assemble the Ghosts: Dip the base of a large marshmallow into the melted chocolate, coat well, and place on a parchment-lined baking sheet. Stack two additional marshmallows on top to create the ghost figure.

Chill the Marshmallow Base: Chill in the refrigerator for about 10-15 minutes to firm up the chocolate and stabilize the structure.

Coat the Ghosts: Once set, coat the entire marshmallow figure with melted white chocolate to enhance the ghostly appearance.

Add Eyes and Features: While the coating is wet, attach candy eyes and use the edible marker for facial details. Allow to set for about 30 minutes.

Final Touches: Dust the finished marshmallows with powdered sugar just before serving for an appealing look.