In a small bowl, stir together smoked paprika, onion powder, garlic powder, kosher salt, black pepper, dried thyme, dried oregano, and cayenne pepper (adjust the cayenne to your heat preference). (recipe note #1)
Cook the Shrimp
Add shrimp to a large bowl; drizzle over 1 tablespoon of the olive oil and sprinkle with blackened seasoning. Toss well to coat.
Heat remaining olive oil and butter in a large skillet over medium-high heat until sizzling. Add shrimp in a single layer (medium shrimp need about 2 minutes per side; larger ones a bit longer) and cook, undisturbed, for 2 minutes; flip with a thin spatula and cook about 2 minutes more, until shrimp is just cooked through.
Transfer to serving bowl or platter and garnish with fresh parsley (or cilantro) if desired and lime wedges; serve hot.
Video
Notes
This is a small-batch version of my Homemade Blackened Seasoning - you can use 2 tablespoons of a store-bought variety if you prefer. If using salted butter, you may want to cut the kosher salt slightly.
If starting with frozen shrimp, thaw overnight in the fridge, then pat very dry with paper towels. Excess surface moisture keeps the spices from charring and makes the shrimp steam instead of blacken.