Mix together the powdered sugar and cake mix and add to a gallon ziploc bag. Shake to combine.
Measure out the cereal in a large bowl and set aside.
In a microwave safe bowl place chocolate chips and coconut oil (or margarine). Microwave on high for 45 seconds and stir until smooth. If not completely melted microwave in 15 sec intervals until melted and smooth.
Pour the melted chocolate over the chex and stir to coat evenly.
Add the cereal mixture to the gallon bag and shake to coat completely.
Spread over a parchment or foil lined baking sheet until completely cool. Add sprinkles if desired.
Store in air tight container until ready to enjoy.