Bring a large pot of salted water to a boil. Cook spaghetti according to package instructions until al dente, around 8-10 minutes. Reserve 1/4 cup pasta water before draining.

In a skillet over medium-high heat, add ground beef and brown for 5-7 minutes, draining excess fat as necessary.

Add minced garlic and grated ginger to skillet. Sauté for 1 minute until fragrant.

Stir in soy sauce, chili oil, brown sugar, and rice vinegar, allowing to simmer for 2-3 minutes.

Add cooked spaghetti to skillet, tossing gently to coat. If too thick, add reserved pasta water until desired consistency.

Remove from heat, drizzle sesame oil, and stir in green onions and sesame seeds. Toss to combine.

Serve hot, garnished with extra sesame seeds or chili oil if desired.