You have to clear the Icing at the top as quickly as you can. Whether you do this by matching candies adjacent to them or by activating special candies, that’s up to you. Just don’t miss out on opportunities to match candies adjacent to the Icing.
With candies of five colors on the playing field you shouldn’t have too many problems making special candies. Try to make as many special candies as you can and when possible combine them to maximize their effects.
Match candies near the bottom of the playing field as often as you can. Doing this will shift the largest amount of candies, hopefully start a chain reaction and create new opportunities to make special candies. While matching candies at the bottom it can be easy to ignore making special candies at the top of the playing field. So pause after every move and glance at the entire playing field to see whether you can make special candies.