In a large saucepan, bring the chicken broth to a boil, then lower the heat and simmer gently.
In a wide, oval pot or a large skillet, melt the butter in the EVOO, 2 turns of the pan, over medium heat. Add the pancetta and cook until lightly browned, 2 minutes. Add the onion, garlic, carrots, bay leaf and thyme; season with salt and pepper. Cook until softened, about 5 minutes. Push the veggies to the side of the pan and add the spaghetti. Lightly toast the spaghetti, turning occasionally, 3 to 4 minutes. Stir in the wine and simmer until completely absorbed, about 5 minutes. Stir in the beans, then add a ladleful of the warm chicken broth. Keep adding the broth a few ladlefuls at a time, turning the noodles to absorb the liquid before adding more, as if you were making a risotto. Cook until most of the broth has been absorbed and the spaghetti is cooked until al dente, 15 to 20 minutes. Discard the bay leaf and thyme sprigs, then stir in the parmigiano-reggiano. Remove from the heat and stir for 1 minute.
Serve the creamy spaghetti in bowls, topped with the parsley.