For cornbread, combine the first 4 ingredients in a bowl. Combine 2 eggs, milk and oil; stir into dry ingredients just until moistened. Pour into a greased 9-in. square baking pan. Bake at 400° for 18-20 minutes or until a toothpick comes out clean. Cool on a wire rack.
In a skillet, saute mushrooms, celery and onions in butter until tender. In a large bowl, beat remaining eggs add broth, soup, almonds, poultry seasoning, pepper and vegetables. Crumble cornbread over mixture.
Pour into a greased 13x9-in. baking dish. Bake, uncovered, at 350° for 45-50 minutes or until a knife comes out clean.