1. Cut bread loaf in half lengthwise. Brush melted butter evenly onto cut sides of bread halves.
2. Stir together onion, jalapeño pepper, and next 5 ingredients, and spread mixture evenly over buttered sides of bread halves. Place bread halves, buttered sides up, on a baking sheet, and sprinkle evenly with 1 1/2 teaspoons Creole seasoning.
3. Bake at 350° for 18 to 20 minutes or until brown and bubbly. Let stand 5 minutes; cut crosswise into 1-inch-thick slices, and serve immediately.
Note: To make ahead, wrap prepared unbaked bread halves in aluminum foil, place in a large zip-top plastic freezer bag, and freeze up to 1 month. To bake frozen, remove bread halves from freezer bag, and place foil-wrapped bread on a baking sheet. Bake at 350° for 10 minutes or until thawed. Remove foil, return to baking sheet, buttered sides up, and bake 8 to 10 minutes or until brown and bubbly. Let stand 5 minutes, and cut bread halves as directed.