Place waxed paper on large cookie sheet. Spread 1 cup of cookies, 1 cup of pretzel pieces and about 3/4 cup of the candy corn into a 13×9-inch rectangle on the waxed paper.
Place chocolate and shortening in glass measuring cup and heat in microwave for about 1 1/2 minutes. Stir and then microwave for about another 30 seconds until melted and smooth.
Drizzle melted chocolate immediately over cookie mixture, spreading with greased spatula (if needed) to coat evenly. Top with reserved cookies, pretzels, candy corn and colored sprinkles. Work quickly before chocolate hardens.
Place into refrigerator or freezer until firm. Remove and gently break apart into small pieces for serving. Store in airtight container.
*Substitute large chocolate sandwich cookies for bite-sized, if desired (break them into pieces).
*Substitute M&M candies for chocolate sandwich cookies, if desired.
*Substitute Cheerios for pretzels, if desired.
*For easy breaking, use a sharp knife to press into the cookie bark- it will break apart easily.