Place candy canes into a sturdy resealable plastic bag, place bag atop a folded kitchen towel, and lightly crush the candy canes into small pieces with a hammer.
Combine chocolate cookie crumbs and confectioners' sugar in a bowl, mixing until crumbs are coated; stir melted margarine into cookie crumbs. Press the cookie crumb mixture evenly into the bottom of the prepared jelly roll pan.
Heat confectioners' candy coating in a microwave-safe bowl in microwave for 50 seconds on high; stir. Continue heating candy for 15-second intervals, stirring each time, until melted, warm, and smooth. Spread candy over cookie crumb crust and smooth top with a spatula; let stand about 10 minutes to firm candy layer.
Sprinkle crushed candy canes evenly over the confectioners' coating; let stand about 2 minutes. Press candy cane pieces lightly into the coating using a piece of waxed paper. Freeze peppermint bark until set, about 1 hour. Remove from foil and break bark into pieces. Store in refrigerator.