Start by cooking the pasta in salted boiling water according to the time listed on the package instructions.
In a skillet, spray cooking oil. Season shrimps with salt, pepper, and paprika and cook for about 1-2 minutes on each side, then set aside.
Mince garlic, onion, and chilis and sauté in skillet for about 3 minutes, or until the onions begin to soften.
Pour in the crushed tomatoes, breaking down the bigger tomato pieces with a spatula or wooden spoon. Add in the rosemary sprigs and bring down to a simmer to let the flavor develop. Let simmer for about 10 minutes.
Strain the pasta and reserve some pasta water. Pour the pasta in the sauce and mix thoroughly.
Add in the half and half and mix thoroughly, then add back in the shrimps.
Remove from heat, top with basil and parmesan cheese if desired, and enjoy!