The filbert is a type of hazelnut that got its name because it ripens near the feast of St. Philbert, a seventh-century monk. The terms filbert and hazelnut are most often used interchangeably.Shelled filberts can be eaten whole, chopped, or ground. They can be added to cookies, cakes, and other desserts, or used in salads or to make a savory butter to flavor entrï¿½es and side dishes. Like many nuts, roasting filberts brings out their flavor. After roasting, filberts should be rubbed in a cloth while still hot to remove their skins.