Heat frying oil to 350. Prepare a plate with a paper towel over it.
Prepare two shallow bowls. In one bowl, mix buttermilk and hot sauce. In another bowl, mix flour, cornmeal, salt, paprika, and cayenne pepper.
Wash shrimp and pat them dry with a paper towel.
Batter shrimp by dredging them in flour mixture first, then in buttermilk, and then again in flour mixture.
Fry shrimp in batches (or all at the same time, depending on the size of the pot used for frying) for about 4 minutes, until they are golden brown. Take shrimp out with a metal slotted spoon onto the prepared paper towel.
Cook pasta while preparing shrimp. Drain and set aside in a big bowl.
Prepare sauce:
In a sauce pot, melt butter over medium heat. Add sliced bell pepper and cook until softened.
Sprinkle flour over the peppers and mix well. While mixing, start slowly adding milk. Keep mixing and add paprika, cayenne pepper and some salt.
Cook over medium heat, stirring often, until it starts to thicken.
Add the cheeses while slowly stirring (leave a little bit of Mozzarella for topping). Keep stirring slowly until all smooth. Taste to see if you need to add more salt.
Mix cheese sauce into pasta.
Fold in shrimp. Transfer into a lightly greased casserole dish. (1.5 - 2 quart dish will work.) Spread some shredded Mozzarella on top.