Boil macaroni in salted water until al dente (about 7 minutes). Drain and set aside.
Heat olive oil in a frying pan over medium heat. Sauté onions and garlic until fragrant.
Add diced bell peppers and cook until softened, about 5 minutes.
Stir in chili flakes, smoked paprika, cumin, and cayenne pepper. Toast spices for 1 minute.
Pour in tomato sauce and stir well. Simmer for 5 minutes until thickened.
Mix in heavy cream, salt, and black pepper. Cook for 2 more minutes.
Combine the cooked macaroni with the sauce and mix until evenly coated.
Sprinkle shredded cheddar cheese and stir until melted.
Serve hot, garnished with fresh herbs if desired.