Black and white cookie

Black-and-white cookies, half-and-half cookies, and half-moon cookies are similar round cookies iced or frosted in two colors, with one half vanilla and the other chocolate. They are found in the Northeastern United States and Florida. Black-and-white cookies are flat, have fondant or sometimes royal icing on a dense cake base, and are common in the New York metropolitan area. Half-moon cookies are slightly dome-shaped , have frosting on a fluffy angel cake base, and are common in Central New York and Boston, Massachusetts. The Amerikaner is a similar cookie in German baking.

Source: Wikipedia