Oreo

Oreo is a trademark for a popular sandwich cookie by the Nabisco Division of Kraft Foods. The current design consists of a sweet, white filling commonly referred to as 'cream' or 'creme', sandwiched between two circular chocolate or golden cookie pieces.
Over 491 billion Oreo cookies have been sold since they were first introduced, making them the best selling cookie of the 20th century. Its most recent packaging slogan is "Milk's Favorite Cookie", which is a slight change from the original, "America's Favorite Cookie" (though some packages still use the original slogan).