By Veronika Bondarenko The Tex-Mex chain is partnering with a fancy New York bakery. Dessert has, traditionally, been many a fast food company’s weak point — while favorites like the McDonald’s (MCD) – Get McDonald’s Corporation Report McFlurry and Wendy’s (WEN) – Get Wendy’s Company (The) Report’s Frosty do exist, most fast food menus are small in scope and rarely move beyond milkshakes or the occasional pie or donut hole. That’s why it comes as that much more of a surprise that the Yum! Brands (YUM) – Get Yum! Brands Inc. Report company is partnering with Milk Bar — a New York dessert chain …