Peel the outer papery skin off the onions. You can either slice them into thick wedges or keep them whole and cut a deep “X” across the top, stopping about three-quarters of the way down so the onion stays together but opens up like a flower.

In a small mixing bowl, combine the softened butter, Old Bay seasoning, garlic powder, smoked paprika, onion powder, lemon juice, and hot sauce. Mix until the spices are evenly distributed throughout the butter.

Place each onion on a large square of heavy-duty aluminum foil. Generously slather the seasoned butter mixture all over the onions, making sure to get some into the crevices or between the wedges. Fold the foil up tightly around the onions to create a sealed pouch that won’t leak.

Preheat your oven to 400°F (200°C). Place the foil packs on a baking sheet to catch any potential drips and bake for 45 to 50 minutes. If you are using a grill, place them over medium heat for about 35-40 minutes until the onions are fork-tender.

Carefully open the foil packs, being mindful of the hot steam. Spoon the collected butter sauce from the bottom of the pack back over the onions. Garnish with fresh parsley before serving.