Place the popped popcorn in a large bowl with the broken pretzel and M&M's.  Heat the candy coating in the microwave in 30 second intervals, stirring after each time, until melted and smooth.

Drizzle the candy coating over the popcorn mixture and stir to coat.  The pretzels and M&M's will sink to the bottom, so make sure to get those stirred in and coated with the rest of the popcorn. 

Spread out on a large piece of wax paper, top with a few colorful sprinkles if desired and let cool.  Break into pieces and serve.