MARINATE:
In a large bowl, mix olive oil, 2 tablespoons of melted butter, garlic, lemon juice, smoked paprika, chili powder, salt, and black pepper.
Add the shrimp and toss until evenly coated. Marinate for 15-30 minutes.
GRILL:
Preheat a grill or grill pan to medium-high heat.
If using skewers, thread the shrimp onto skewers for easier handling.
Place shrimp on the grill and cook for 2-3 minutes per side, until they turn pink and slightly charred. Avoid overcooking to keep them tender.
GARLIC BUTTER:
While the shrimp are grilling, combine the remaining melted butter with any leftover marinade. Brush this mixture onto the shrimp during the last minute of grilling.
SERVE:
Transfer the grilled shrimp to a serving platter.
Garnish with fresh parsley and grated Parmesan cheese, if desired.