In large pot of boiling salted water, cook pasta according to package instructions. Reserving 1⁄2 cup of the cooking liquid, drain. Set aside.
Meanwhile, season shrimp with 1⁄2 tsp of the salt, 1⁄4 tsp of the pepper and 1⁄4 tsp of the paprika. In large skillet, heat oil over medium-high heat. Add shrimp and cook, stirring, until pink and cooked through, 1 to 2 minutes per side. Transfer to plate.
In same pan, melt butter over medium heat. Add onion powder and whisk for 30 seconds. Whisk in wine, scraping up browned bits from bottom of pan. Cook until a quarter of the liquid remains, 2 to 3 minutes. Add garlic and cook until fragrant, 1 minute.
Whisk in cream and red pepper flakes (if using); bring to a gentle simmer and reduce heat to low. Cook until sauce slightly thickens, 2 minutes.
Sprinkle in Parmesan, whisking to combine. Remove from heat, stir in parsley and sprinkle with remaining pinch each salt, pepper and paprika, if desired.
Return pasta and shrimp to pan, adding some of reserved pasta cooking liquid if mixture is too thick. Toss to combine.
To serve, top with more parsley and Parmesan.