Preheat oven to 375°. Spray a 13×9-inch baking dish with cooking spray.
In prepared pan, place mirlitons, cut side down, and 2 tablespoons water; cover with foil.
Bake until just tender, 45 to 50 minutes. Let cool for 10 minutes. Using a spoon, carefully, scoop out center of squash, leaving a ¼-inch-thick shell. Return mirlitons, cut side up, to pan. Sprinkle with salt. Leave oven on.
In a medium skillet, melt butter over medium heat. Add bell peppers, onion, celery, and garlic. Cook, stirring occasionally, until tender, 8 to 10 minutes.
In a large bowl, combine bell pepper mixture, Oyster Cornbread Dressing, spinach, 3 tablespoons cheese, and Creole seasoning. Divide mixture among mirlitons.
In a small bowl, combine bread crumbs, melted butter, and remaining 1 tablespoon cheese. Sprinkle on top of mirlitons. Cover with foil.
Bake until heated through, about 15 minutes. Uncover and bake until golden brown, 10 to 15 minutes more. Garnish with parsley, if desired.
Notes
*We used Tony Chachere’s No-Salt Seasoning Blend.
Recipe by Louisiana Cookin' at https://louisianacookin.com/oyster-dressing-stuffed-mirlitons/