Heat 2 tablespoons of olive oil over medium heat in a large, heavy pot or Dutch oven. Add the pancetta (or bacon) and cook over medium-low heat for 6 to 8 minutes, stirring occasionally, until lightly browned. Add the onions, carrots, celery, squash, garlic, and thyme and cook over medium heat, stirring occasionally, for 8 to 10 minutes, until the vegetables begin to soften. Add the tomatoes, 6 cups of the chicken stock, the bay leaf, 1 tablespoon salt, and 1 1/2 teaspoons pepper to the pot. Bring to a boil, then lower the heat and simmer uncovered for 30 minutes, until the vegetables are tender. Discard the bay leaf. Add the beans and cooked pasta and heat through. The soup should be quite thick but if it's too thick, add more chicken stock (I did not).

While the soup is simmering, cook the pasta. Bring a large pot of salted water to a boil. Add 1 cup of pasta and cook according to the package instructions. Drain, and set aside.

Add the spinach, and toss with 2 big spoons (like tossing a salad). Cook just until the leaves are wilted. Stir in the white wine and pesto. Depending on the saltiness of the chicken stock, add another teaspoon or two of salt to taste (I did not add any). Pour into bowls, sprinkle with Parmesan cheese and serve hot.