Heat the olive oil in a large skillet with deep sides over medium high heat. Add the onion and sage and let them get fragrant for a minute. Then brown the sausage with the onion and sage, breaking it up as it cooks. Season the mixture with the salt, pumpkin pie spice and crushed red pepper as it cooks too. Then pour in the pumpkin puree, apple cider and milk. Give the sauce a good stir and let it come to a gentle boil. Reduce the heat to low and let it all simmer together for 15 minutes.

While the sauce cooks, get a large pot of water on the stove and bring it to a boil. Salt it generously, then cook the rigatoni in it just until tender for about 8-10 minutes. The sauce should be ready by this point. Drain the pasta and transfer it to the sauce. Toss it all together well and take the pan off of the heat. Scoop the pasta into bowls and serve immediately with extra fresh sage on top for garnish!