Preheat oven to 375°. Spray a 13x9-inch baking dish with cooking spray.
In a large saucepan, heat oil over medium heat. Add onion, bell pepper, and celery; cook, stirring frequently, until almost tender, 5 to 7 minutes. Stir in garlic and thyme; cook until fragrant, about 1 minute.
In a large bowl, place Buttermilk Cornbread; crumble half of cubes. Stir in onion mixture, crawfish, broth, eggs, poultry seasoning, salt, black pepper, and red pepper. Spoon into prepared pan. Cover with foil.
Bake for 15 minutes. Uncover and bake until golden brown, 20 to 30 minutes more. Garnish with thyme, if desired.
Buttermilk Cornbread
Preheat oven to 425°.
Place a 12-inch cast-iron skillet in oven for 10 minutes.
In a large bowl, whisk together cornmeal, flour, baking powder, salt, and baking soda.
In a medium bowl, whisk together buttermilk, melted butter, and eggs. Pour buttermilk mixture into cornmeal mixture; stir just until combined. Pour mixture into hot skillet.
Bake until a wooden pick inserted in center comes out clean, 20 to 25 minutes. Invert cornbread onto a wire rack. Let cool for at least 20 minutes.
Recipe by Louisiana Cookin' at https://louisianacookin.com/crawfish-cornbread-dressing/