Cook the pasta in a large pot of boiling salted water until al dente, according to the box. Drain, reserving 1/4 cup of the cooking liquid.
In a large sauté pan, heat 1/2 of the olive oil over medium heat. Add the onions, and jalapeno (if using) and cook, stirring, until soft, about 5 minutes. Add the garlic, paprika, cayenne, oregano, and salt. Cook, stirring for 1 minute.
Add the white wine and cook over high heat until nearly all evaporated. Reduce heat to medium low, add the cream and pasta water cooking and stirring occasionally until slightly reduced and thickened. Stir in 1/2 the lemon juice and parmesan until melted, turn off heat and keep warm.
In the meantime, toss the shrimp with some additional paprika, cayenne, and salt, to taste. Heat remaining oil in a pan and cook for 1 - 2 minutes per side. Finish with some more of the lemon juice.
Add the cooked pasta to the cream mixture and toss to coat. Cook on medium low until the pasta is warmed through, about 1 minute. If the sauce is still too thin keep cooking the pasta will allow it to thicken. Stir in some of the shrimp into the pasta mixture, reserving a few to garnish. Serve with more grated Parmesan, and Italian parsley.