Step 1Bring a large pot of salted water to boil.
Step 2Meanwhile, bring the chicken broth to a boil in a saucepan over medium-high heat. Add the squash, reduce the heat to medium-low, cover and simmer until the squash is tender, about 10 minutes.
Step 3While the squash is cooking, add the rigatoni to the boiling water. Reduce the heat to medium and cook until the pasta is tender yet still firm, about 12 minutes.
Step 4Heat the olive oil in a deep, 12-inch skillet over medium-high heat. Add the sausage and break it up with a wooden spoon. Cook until it's no longer pink, 3 to 4 minutes. Add the onion and bell pepper and cook until tender, about 4 minutes.
Step 5Add the squash with its cooking liquid to the skillet. Drain the pasta and add to the skillet along with the whipping cream and sage. Cook, stirring, just until heated through, about 2 minutes. Toss with the cheese and pepper to taste, if desired, and serve.