Preheat the oven to 450°F. Fill a medium pot (or large for 4 servings) 3/4 of the way up with salted water; cover and heat to boiling on high. Wash and dry the fresh produce. Line a sheet pan with foil. Cut off and discard the ends of the squash. Quarter lengthwise; using a spoon, scoop out and discard the pulp and seeds. Cut the squash crosswise into 1/2-inch pieces. Transfer to the sheet pan; drizzle with olive oil and season with salt and pepper. Toss to coat and arrange in an even layer. Roast 18 to 22 minutes, or until tender when pierced with a fork. Remove from the oven.

Meanwhile, add the pasta to the pot of boiling water. Cook, stirring occasionally, 7 to 9 minutes, or until al dente (still slightly firm to the bite). Turn off the heat. Reserving 1/4 cup of the pasta cooking water (or 1/2 cup for 4 servings), drain thoroughly and return to the pot.

In a medium nonstick pan (or large for 4 servings), heat a drizzle of olive oil on medium-high until hot. Add the sausage; break the meat apart with a spoon. Cook, without stirring, 3 to 4 minutes, or until lightly browned. Continue to cook, stirring frequently, 4 to 5 minutes, or until browned and cooked through. Leaving any browned bits (or fond) in the pan, transfer to a bowl.

Meanwhile, halve, peel, and thinly slice the shallot(s). In the same pan, heat a drizzle of olive oil on medium-high until hot. Add the sliced shallot(s) and as much of the red pepper flakes as you'd like, depending on how spicy you'd like the dish to be; season with salt and pepper. Cook, stirring occasionally, 2 to 3 minutes, or until softened. Add the spinach. Cook, stirring frequently, 1 to 2 minutes, or until combined and the spinach is wilted. Turn off the heat.

In a bowl, combine the ricotta and a drizzle of olive oil; season with salt and pepper. To the pot of cooked pasta, add the cooked sausage, cooked spinach, roasted squash, pesto, cream (shaking the packet before opening), and half the reserved pasta cooking water. Cook on medium-high, stirring constantly, 1 to 2 minutes, or until combined and the pasta is coated (if necessary, gradually add the remaining cooking water to ensure the pasta is thoroughly coated). Turn off the heat. Taste, then season with salt and pepper if desired. Serve the finished pasta topped with the seasoned ricotta. Enjoy!