Measure cereal and mini marshmallows in a large bowl and set aside.
Melt mini Hershey's Kisses and shortening in the microwave on high for 60 seconds. Stir and return to the microwave for 15-second intervals, stirring until smooth.
Pour the melted chocolate over the cereal and mini marshmallow and stir to coat.
Add the powdered sugar and stir to coat.
Optional: Stir in 1/2 cup mini Hershey's Kisses and 1/4 cup Jet Puffed Mallow Bits
Spread on waxed paper to cool and set.