Prepare cornbread mix according package directions. Let cool completely (about 30 minutes). Coarsely crumble cornbread.
Rinse turkey, and pat dry. Sprinkle with salt and pepper.
Melt butter in a large skillet over medium heat; add turkey to skillet; skin side down, and cook 3-4 minutes or until browned. Remove from skillet. Add onion and next 3 ingredients to skillet, and saute 3-5 minutes or until tender.
Stir together onion mixture, stuffin mix, eggs, chicken broth, and crumbled cornbread in a large bowl.
Place stuffing mixture in a lightly greased 6 1/2 quart slow cooker. Top with turkey, skin side up. Cover and cook on LOW 4 hours or until a meat thermometer inserted into thickest part of breast registers 170 degrees and stuffing registers 165 degrees. Remove turkey from slow cooker and allow to stand 15 minutes before serving.