Boil the Spaghetti: Bring a large pot of water to a rolling boil, add salt, and cook spaghetti until al dente, about 8-10 minutes. Reserve 1/4 cup cooking water, drain, and set aside.

Brown the Ground Beef: In a skillet, heat 1 tbsp oil over medium-high heat. Add ground beef, breaking it apart as it cooks until no longer pink, about 5-7 minutes.

Sauté Aromatics: Lower the heat, add garlic and ginger, sauté for 1 minute until fragrant and garlic is golden.

Create the Sauce: Stir in soy sauce, chili oil, brown sugar, and rice vinegar. Let simmer for 2-3 minutes until the sauce thickens.

Combine with Spaghetti: Add reserved spaghetti to the skillet, tossing well to coat. Use reserved pasta water if needed to adjust sauce consistency.

Final Touches: Drizzle sesame oil, add green onions and sesame seeds, then serve immediately.