Focus on taking the matches you can right away and start working down through the blocks. Try to avoid the chocolate, but eventually you will hit them. Focus on what you need as opposed to the chocolate, you will always have matches to make.
Thanks to Matthew Dean
Patricia Frederick’s Tips for Candy Crush Level 127
You need to break the blocks to give room for more candies to fill in, but that will unleash the chocolate, so make any specials you can to battle it. Don’t waste a lot of moves trying to clear it completely—it’s not necessary—just keep it contained.