Line a 9×13-inch baking dish with parchment paper and spray with non-stick cooking spray.
Place Coco Roos and 1 cup whole almonds in a large bowl. Melt chocolate candy coating according to package directions. Pour melted candy coating over cereal and almonds and toss to coat. Add marshmallows and gently toss until cereal, almonds and marshmallows are all evenly coated in candy coating.
Immediately press mixture evenly into prepared dish using lightly greased parchment paper to press down on the mixture. Sprinkle with ¼ cup crushed almonds and 1 cup mini marshmallows, if desired.
Allow bars to set in a cool, dry place for about 10 minutes. Cut into squares.