Preheat the oven to 350°F.
Trim a small slice off the top and bottom of each onion, keeping the root intact, then peel off the skins.
Scoop out the center of each onion, leaving about a 1-inch border and hollowing halfway down.
Place each onion on a foil-lined baking sheet.
Add 1 teaspoon chicken stock base and 1 teaspoon Worcestershire sauce into each onion cavity.
In a small bowl, mix Creole seasoning, smoked paprika, parsley, garlic powder, and black pepper.
Sprinkle about half of the seasoning into each onion, then add 2 tablespoons of butter into each cavity.
Sprinkle the remaining seasoning evenly over the onions.
Wrap each onion tightly in foil.
Bake for about 1 hour until the onions are tender.
Carefully unwrap and serve warm.