Begin by melting 1 cup of white chocolate chips mixed with 1 tablespoon of vegetable shortening in a microwave-safe bowl. Heat in 30-second intervals, stirring between each, until the chocolate is fully smooth and glossy. This process usually takes about 1-2 minutes.

Take a large marshmallow and dip the bottom into the melted white chocolate, ensuring it's coated well. Place this marshmallow, chocolate side down, onto a parchment-lined baking sheet. Stack two additional marshmallows on top using the chocolate as glue to hold them together; this creates the iconic Stay Puft shape. Allow the marshmallow structure to rest and set for about 10-15 minutes until stable.

Once the base has set, gently coat the entire marshmallow stack with the remaining melted white chocolate. Use a spoon to ensure an even layer over every surface. Quickly add candy eyes while the chocolate is still soft, adjusting their placement until they look just right. Allow this layer to set for about 10 minutes at room temperature.

After the chocolate has hardened slightly, dust your marshmallows with powdered sugar to create a classic appearance. Use the black edible marker to draw a playful smile or any facial features you desire.

Let the completed marshmallows cool at room temperature for about 30 minutes, allowing the chocolate to harden completely. Avoid refrigeration to maintain their smooth finish. Once set, these marshmallows are ready to be served at parties or shared with friends.