Dear Cathy the Cartoon and Other Chocolate Enthusiasts, It seems like every day is designated as some sort of holiday honoring a food, group of people, cause, or fictional character. For example, did you know that February 22 is National Margarita Day? Or that June 2 is National Doughnut Day? Or that August 20 is World Mosquito Day? I can’t believe that doughnuts and margaritas only get the U.S., but mosquitos are honored worldwide. So rude. I’m personally not a huge fan of mosquitos, but I am a fan of chocolate. So when American Express invited me to choose my favorite local chocolatier…