Combine mini marshmallows and butter in microwave safe bowl, heat in 30 second increments until melted. Stir to mix.
Add cereal and stir until combined, cool for 10 minutes.
Spray hands with cooking spray and shape mixture into egg shapes with flat bottoms.
Place on parchment paper and let rest for 30 minutes.
Melt the white chocolate according to the package instructions and dip the top of each treat in the melted chocolate.
Return to parchment paper and let chocolate harden for 30 minutes.
Melt the chocolate chips in 30 second increments until melted, then transfer it to a piping bag. Cut the tip off the bag and pipe two eyes and a mouth on the front of each ghost. Allow the chocolate to harden before serving.
Notes
Storage: Store in airtight container at room temperature for up to one week.