I'd spotted these cookies on the Instructables website and loved the idea, but it took me forever to get around to making them. One of my favorite haunts at lunchtime is the Broadway Panhandler store which has everything from overpriced pans and knives to sparkle gel for cookies. I bought the latter, along with flower sprinkles and gel food coloring. I wasn't so sure about using the recipe from the original instructions after reading the posts, so I went with a recipe which other people recommended because it doesn't spread during baking: No Fail Sugar Cookies
It took me a while to get a method of rolling the dough and mixing the colors. I tried to follow the instructions, but in the end, I took globs of different colors, rolled them together like playdoh and hoped it would create cool stripes of colors, which it usually did. Just make sure not to overmix the colors or you'll lose the striping. Baking was 8-10 min per batch. I cooled them, painted them with white sparkle gel and sprinkled them with flowers, just like a unicorn would.