Start by boiling your noodles in salted water until just tender. Make sure not to overcook them so they stay slightly firm. Reserve some pasta water before draining for later use.
Heat oil in a pan and add sliced sausage pieces. Cook until browned and slightly crispy on the edges for deeper flavor. This step releases oils that will build your sauce base.
Add garlic, ginger, and gochujang into the pan with sausage. Stir well to coat everything evenly in the spicy paste. Add soy sauce, sugar, and a splash of noodle water to loosen it.
Add cooked noodles into the sauce and toss thoroughly. Let everything mix until noodles are fully coated and glossy. Top with spring onions and crispy onions before serving hot.