The only way to clear the Chocolate is by hitting it with special candies. That’s why you have to focus on making special candies that will hit the Chocolate. While most special candies are ok to make, don’t activate Jelly Fishes on their own because it will only remove one layer of Chocolate, which will regenerate automatically the next move. Instead of using Jelly Fishes on their own combine them with other special candies.
Also, you will have to make and activate special candies back to back otherwise the Chocolate will just regenerate, wasting your moves in the process.
The key to completing this level is probably the Coloring candy dispenser at the bottom of the playing field. Try to make special candies that will clear the candy below the dispenser so that you get to use the Coloring candies it dispenses. Although you don’t have to combine the Coloring candy with a special candy, as you can see in the video above, combining it with a special candy can have a nice effect.