Bring a large pot of salted water to a boil. Add the cavatelli and cook for 2 minutes less than the package directions. Reserve 1 1/2 cups of pasta water, then drain well.
Meanwhile, add the pancetta and olive oil to a large skillet over medium-high heat. Cook, stirring often with a wooden spoon, until the pancetta is crispy, about 8 minutes. Add the shallots and cook another minute until fragrant. Add the tomatoes and season with 1/8 teaspoon salt. Cook, stirring often, until the tomatoes begin to soften, about 4 minutes. Add the cavatelli to the skillet along with 1/2 cup of the pasta water. Scatter the Gorgonzola over the pasta and stir to combine. Continue to stir, adding pasta water as needed, until a light creamy sauce is formed. Add the spinach and toss to combine. Cook for another minute, until the spinach is just barely wilted. Serve hot.