In a large pot or deep skillet, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes until translucent.
Stir in the minced garlic, red and green bell peppers, Cajun seasoning, and smoked paprika. Cook for another 3-4 minutes until the peppers are softened.
Add the pasta to the pot, followed by the heavy cream and vegetable broth. Stir everything together, making sure the pasta is submerged in the liquid.
Bring the mixture to a simmer, then reduce the heat to low. Cover and cook for about 12-15 minutes, stirring occasionally until the pasta is al dente and has absorbed most of the liquid.
Add the cherry tomatoes and spinach to the pot. Stir gently to incorporate them and cook for an additional 2-3 minutes until the spinach wilts.
Taste the pasta and season with salt and pepper as needed. If you prefer a creamier texture, you can add a bit more heavy cream at this point.
Remove from heat and let it sit for a few minutes. Serve warm, garnished with chopped parsley and a generous sprinkle of grated Parmesan cheese.
Notes
For a creamier texture, add more heavy cream as desired.