These sweet crystals, made from sugar cookie dough and topped with royal icing, are the ultimate rock collection—beautiful, colorful, and totally delicious. As a professional cookie decorator, dreaming up unique designs with a hint of realism is my favorite part of the baking process. These edible gems also embody the whimsy of natural shape and pattern, so don’t be intimidated—the process embraces imperfection, making them the perfect project for a first-time cookie decorator. Give them as gifts, add playfulness to any party platter, or use them...