Preheat oven to 375 degrees. Spread cornbread and bread on two rimmed baking sheets and bake until dry and golden, about 15 minutes. Meanwhile, in a medium skillet, cook bacon over medium until fat is rendered and bacon is crisp, about 5 minutes. Add onion, celery, and garlic and cook until translucent, about 4 minutes. Stir in sage and transfer to a large bowl.
Add cornbread, bread, eggs, broth, parsley, 1 1/2 teaspoons salt, and 1/2 teaspoon pepper to bowl and toss until combined. Let sit 5 minutes, then toss again. Reserve 4 1/2 cups for turkey, then spoon remaining stuffing into a 9-inch square baking dish. Bake until top is golden brown, 20 to 25 minutes.