There’s a reason why T-shirts with slogans like “I Put Butter on My Butter” and “Butter Together” exist. This is one food with an extremely loyal fan club. Beloved by folks around the globe, butter is a big fat deal for one Midwest state in particular. In fact, butter is so beloved in Wisconsin that it’s actually written into state code that restaurants cannot knowingly serve a common competitor as a substitute for butter unless specifically asked. Ahead, a food historian and a dairy expert dish out insights on how butter became one of the most important ingredients in the Badger State. Then stick around to find out what item is illegal to serve and to learn which Wisconsin butter recipes you must try on your next trip to America’s Dairyland . The History of Butter in Wisconsin Diced butter in a bowl.…