To prepare corn bread, lightly spoon flour into a dry measuring cup; level with a knife. Combine flour and next 5 ingredients (through baking soda) in a medium bowl. Combine buttermilk and 2 eggs; stir well. Add to flour mixture; stir just until moist. Spoon into an 11 x 7-inch baking dish coated with cooking spray. Bake at 425° for 20 minutes or until lightly browned and a wooden pick inserted in center comes out clean. Cool on a wire rack. Cut into 1/2-inch pieces; arrange on a large baking sheet.
Reduce oven temperature to 375°.
Bake corn bread pieces at 375° for 20 minutes, stirring occasionally.
To prepare stuffing, combine 3 tablespoons sugar and the next 4 ingredients (through egg white); set aside.
Melt butter in a large nonstick skillet over medium-high heat. Add onion, poblano, bell pepper, and garlic; sauté 7 minutes or until tender. Add cumin and corn; cook for 5 minutes. Combine corn bread pieces, egg mixture, poblano mixture, cheese, broth, and cilantro in a large bowl; toss well. Spoon into a 13 x 9-inch baking dish coated with cooking spray; cover with foil. Bake at 375° for 30 minutes. Uncover; bake 5 minutes or until top of dressing is slightly crisp.