In a small bowl, combine the melted unsalted butter with the extra virgin olive oil, creating an emulsified base for the marinade. Stir in the minced garlic, Cajun seasoning, salt, freshly cracked black pepper, smoked paprika, and red pepper flakes. Add the lemon juice and Worcestershire sauce, whisking until the seasonings are fully dissolved and distributed. This aromatic foundation will coat the shrimp evenly and build deep, complex flavors during cooking.

Pat the peeled and deveined shrimp dry with paper towels—this ensures they'll develop better color and texture in the oven. Add the shrimp to the marinade from Step 1 and toss gently but thoroughly to coat every piece. Let the shrimp sit in the marinade for 10 minutes at room temperature, allowing the flavors to begin penetrating the delicate meat. I find that this short marinating window is perfect for shrimp—any longer and the acid from the lemon juice can start to cook the exterior.

Preheat your oven to 425°F. Arrange the marinated shrimp in a single layer on a rimmed baking sheet or shallow roasting pan, spacing them so they're not crowded—this allows hot air to circulate for even cooking. Pour any remaining marinade from the bowl over the shrimp. Roast for 8 minutes, then flip each shrimp carefully and continue roasting for another 7 minutes until the shrimp are opaque, firm, and just cooked through. Don't overcook them or they'll become rubbery.

While the shrimp finishes cooking in the final minutes, melt the 2 tablespoons of butter in a small saucepan or skillet over low heat. Stir in the fresh chopped parsley, which will add a bright, fresh finish to the dish. As soon as the shrimp comes out of the oven, drizzle the warm parsley butter over the top, coating them generously. Serve immediately while everything is hot and the buttery sauce pools around the shrimp.