Pour Chex cereal into large bowl with lid. Melt candy coating according to directions on the package. Once melted, pour candy coating over Chex cereal. Fold together. Add 1/3 of the bottle of sprinkles to the mixture. Fold together. Add another 1/3 of the bottle of sprinkles to the mixture. Fold together. Pour powdered sugar on top of the cereal mixture. Place lid on bowl, seal, and shake. Add M&Ms to the bowl and mix.