Line 2 sheet pans with waxed paper. Place wire racks on top. Slice cakes in half lengthwise. Cut two stars from one half using a 2-1/2-inch metal cookie cutter. Cut trees from remaining pound cake halves, using a 3-inch cookie cutter for a total of about 14 trees. Place on racks.
Remove 3 tablespoons frosting and tint with yellow food coloring. Cover and set aside. Divide remaining frosting in half. Tint one of the portions green; remove half of the green frosting to a resealable bag. Heat the remaining green frosting in a glass measuring cup in the microwave for 5 seconds. Continue heating for 5 seconds at a time, stirring, until the frosting is the texture of slightly whipped cream. DO NOT OVERHEAT! Pour green frosting over half the trees to cover completely; reheat drippings if needed. Repeat this procedure using the white frosting. Heat yellow frosting briefly and coat the 2 stars.
Snip a small corner of the bag with the green frosting. Pipe designs over the white frosted trees as shown. Decorate green cakes with piped white frosting, using candies for accents (remove dragees before eating). Refrigerate 30 minutes until frosting is set. Makes 14 mini tree cakes and 2 stars.