In a medium size microwaveable safe bowl, combine almond bark, peanut butter chips and shortening. Microwave on high for 1 minute, then stir. If more melting, is needed continue to heat at 30 second intervals until completely smooth.
Next, in a large mixing bowl combine Chex cereal, and pretzel sticks. Pour in peanut butter mixture and mix by hand with a spatula until coated.
Pour cereal mixture into a gallon size freezer bag and add powdered sugar. Shake until cereal is everything is blended.
Pour the bag out onto a parchment paper lined cookie sheet. Gently add in M&M’s and sprinkles.