An extruder die assembly and method for using same is disclosed which is designed for adaptation to a wide variety of commercial-grade extrusion devices common in the food industry. The extruder die assembly is inserted into an appropriate compartment within an extrusion device such that a first extrudate is directed down a coaxially aligned passageway within the forming section and combined with a fluid additive in the injection section whereupon the resulting food mass is compressed through a converging nozzle bore in the nozzle section to produce an extruded food product. The forming section and injection section are fabricated as a matching set. The matched set, comprising the forming section and the injection section, when properly aligned and coupled form an internal peripheral reservoir manifold through which a fluid additive may be supplied to at least one and more preferably a plurality of capillary channels which in turn impart a distinct cross-sectional design into a flowing mass of a first extrudate.
