Heat a large 12-inch oven safe, nonstick skillet with a fitted lid over high heat.
Add the olive oil and onion to the skillet. Saute until softened and translucent, about 3-4 minutes. Add the garlic, sage and thyme and stir to combine. Cook until fragrant, about 1 minute.
Add the pumpkin puree, broth, and salt to the skillet, stir to combine, and bring to a simmer. Add the pasta to the skillet, stir to combine.
Reduce the heat to medium, simmer covered, making sure the noodles are submerged in the liquid). Stir occasionally so that the noodles don’t stick to each other or the bottom of the skillet. Cook until the pasta is just tender and the sauce has thickened, about 13-15 minutes.
Remove from heat and stir in the white beans, ricotta cheese and 2 tablespoons of the parmesan. Top with the shredded mozzarella and remaining 2 tablespoons of parmesan cheese.
Transfer to the broiler on the second rack from the top and broil on high until the cheese is melted and slightly browned on top, 2-3 minutes. Garnish with parsley and fresh thyme and serve.