Preheat the oven to 350°.
In a food processor, pulse the bread into coarse crumbs. In a bowl, toss the crumbs with the herbs and butter; season with salt and pepper. Spread the crumbs out on a rimmed baking sheet and bake, stirring once, until golden and crispy, about 15 minutes.
Bring a large pot of water to a boil for the pasta.
In a large skillet, heat the oil, about three turns of the pan, over medium-high. Add the celery, onion, garlic, and bay leaf; season. Cook, stirring often, until softened, 6 to 7 minutes. Add the turkey and cook, stirring occasionally and breaking the meat up with a wooden spoon, until lightly browned, about 5 minutes. Add the wine and cook, stirring often, until absorbed, about 2 minutes. Add the stock. Reduce heat to low and let the sauce simmer while you cook the pasta.
In a second large pot, bring the buttermilk to a gentle simmer over medium heat. Salt the boiling water and add the pasta. Cook for 5 minutes. Drain the pasta, then add to the buttermilk. Simmer the pasta for 3 to 4 minutes. Add the turkey sauce and cheese and toss to combine. Serve the pasta in shallow bowls and top with the breadcrumbs.
