March 6 is a special day for cookie lovers: It’s National Oreo Cookie Day. According to oreo.com, the first Oreo cookie was made at Chelsea Market in 1912 and sold to a New Jersey grocer. But it wasn’t until 1923 that the company began to teach folks to twist the layers apart, then lick the cream and dunk it in milk. In 1974, Oreo “doubled down” and added more cream — double, in fact, to make Double Stuf Oreos (they tripled it with Mega Stuf in 2013).