Cook Pasta
Cook pasta in well-salted water until al dente. Reserve ½ cup pasta water. Drain and set aside.
Caramelize Onions
Heat butter and olive oil in a large pan over medium heat. Add onions and cook slowly until soft and golden, about 8–10 minutes.
Add Garlic
Add in garlic and chili flakes. Cook for 30 seconds until fragrant.
Tomato Paste
Add tomato paste and cook for 1–2 minutes until slightly darker in color.
Make the Sauce
Lower heat and pour in cream. Stir gently until smooth.
Season
Add paprika, garlic powder, salt, pepper, oregano, and soy sauce if using.
Cheese
Stir in parmesan cheese until melted and silky.
Combine Pasta
Add cooked pasta and toss to coat. Use reserved pasta water if needed.
Serve
Serve hot with extra parmesan and chili flakes.