Bring a large pot of salted water to boil. Cook pasta according to package directions until al dente. Reserve 1 cup pasta water, then drain and set aside.
Heat olive oil in a large skillet over medium-high heat. Add sliced sausage in a single layer and cook 5-7 minutes, stirring occasionally, until deeply browned and caramelized.
Reduce heat to medium-low. Add minced garlic and sauté for 1 minute, stirring constantly, until fragrant but not browned.
In a small bowl, whisk together honey, soy sauce, apple cider vinegar, red pepper flakes, and black pepper. Pour into skillet with sausage and garlic.
Simmer sauce for 2-3 minutes, stirring frequently, until slightly thickened and coating the sausage.
Add cooked pasta to skillet. Toss with tongs to coat evenly in honey garlic sauce. If too thick, add reserved pasta water 1 tablespoon at a time until desired consistency.
Remove from heat. Garnish with fresh parsley and serve immediately with Parmesan cheese if desired.