01 -
Heat olive oil and butter in a large skillet over low to medium heat. Add sliced onions and cook slowly for 20-30 minutes, stirring occasionally, until deep golden brown and aromatic.
02 -
Stir in chili oil until well combined. Pour in heavy cream and add garlic powder, salt, and pepper. Simmer gently for 5 minutes to meld flavors.
03 -
Cook spaghetti according to package directions until al dente. Drain and add to skillet with sauce along with some pasta water. Simmer together on medium-high heat for 2 minutes, stirring to combine.
04 -
Remove from heat and sprinkle with fresh parsley. Add a pinch of salt, let cool for 2 minutes, then serve immediately.