Bring a large pot of salted water to a rolling boil over high heat. Add spaghetti and cook until al dente, around 8-10 minutes. Reserve ¼ cup of pasta water, then drain and set aside.

In a large skillet, heat olive oil over medium heat. Add sliced sausage and sear for 6–8 minutes until browned.

In the same skillet, add butter, minced garlic, and red pepper flakes. Sauté for about 30 seconds until garlic is fragrant.

Mix in honey and soy sauce, allowing to bubble for about 1-2 minutes until slightly thickened. Stir in remaining butter.

Return seared sausage to the skillet, tossing to coat in the honey garlic sauce and simmer for an additional 1-2 minutes.

Add drained spaghetti and reserved pasta water to the skillet, tossing for 1-2 minutes until fully coated.

Remove from heat and garnish with parmesan cheese and parsley. Serve immediately.