A cutter assembly for an extruder includes an elongated extrusion member having an opened feed end. The opened feed end is attachable in fluid communication with a first manifold of the extruder. A filling tube extends through the elongated extrusion member, which is attachable to a second manifold of the extruder. An extrusion die is formed in the elongated extrusion member. The extrusion die is shaped to the general shape of a natural food piece. A cutter member has an opened drivable end, an elongated cutter wall, and an opened cutter end with a cutting surface for cutting extrudate to a desired length as the extrudate exits the die. The cutting surface is shaped to the general shape of the extrusion die. The cutter member is disposed at least partially over and reciprocally slidable on the extrusion wall and operably connectable at the drivable end to a drive device of the extruder for reciprocatably sliding the cutting surface of the cutter member over and away from the extrusion die.