Rusk is a type of dry and crispy twice-baked bread that is popularly eaten with tea or coffee. It is known by various names in different parts of the world. In the United States, it is called biscotti, while in the United Kingdom, it is alternatively known as twice-baked bread or hardtack. Other synonyms for rusk include pilot bread, ship's biscuit, and zwieback. Some regional variations of rusk may include mandelbrot or regina bread in Jewish cuisine, and biscochos in Spanish cuisine. Regardless of its name, rusk is a satisfying snack that can last for weeks or even months when stored properly.