Adjust oven rack to middle position and heat oven to 400 degrees. Spray a 13- by 9-inch metal baking pan with vegetable cooking spray, line with parchment, then spray again. Whisk together plant creamer, vinegar, and flax meal; set aside
Heat creamed corn in a large saucepan or small Dutch oven over medium heat. Stir in 1 cup of the cornmeal and continue to cook until mixture starts to stick to the bottom of the pan and make a thick pasty mush. Remove from heat and whisk in milk mixture, then butter.
Mix remaining 1 cup of cornmeal with flour, baking powder, salt, and soda in a medium bowl. Pour wet ingredients into dry; stir until just combined.
Pour batter into prepared pan and bake until firm and golden brown, about 30 minutes. Remove from oven, cool in pan for 5 minutes, then turn onto a wire rack to cool completely. Continue with Herbed Cornbread Stuffing for further instructions.