Stovetop Instructions:

1. Cook Pasta. Bring a large pot of salted water to a boil and cook the pasta until just al dente. The pasta will cook more when it's tossed with the sauce, so you don't want to overcook the noodles. Reserve 1-2 cups of pasta water. Drain pasta and set aside.
2. Make the Pumpkin Cheese Sauce. While the pasta is cooking, make the sauce. In a large deep sauté pan or dutch oven, add the evaporated milk and bring to a simmer over medium heat. Add the pumpkin, spices, and a pinch of salt and pepper, whisk until combined and smooth. Add the shredded cheeses and whisk until melted, smooth, and combined. Taste and add additional salt and pepper, if needed. Lower heat. 
3. Combine Pasta and Sauce. Add the cooked pasta to the cheese sauce. Toss to combine and add pasta water as needed to thin out the sauce and help everything stick together. I usually use about 1 cup, but it will depend on the moisture of your pumpkin puree. 
4. Serve and Enjoy. Enjoy as is or top with some toasted breadcrumbs.

Instant Pot Instructions:

1. Cook Pasta. Add pasta, 4 cups of water, and a heavy pinch of salt to the liner of your instant pot. Close the lid and set valve to sealing. Cook on manual high pressure for 3 minutes. Allow to natural release for 5 minutes before quick releasing the pressure.
2. Stir in Ingredients. There is going to be some water leftover. You can leave it in the pot for an extra creamy and saucy Mac and cheese. Or, you can drain some of the water. With the instant pot still on the warm setting, stir in the evaporated milk, pumpkin, cheese, and spices. Stir until the cheese is melted and the sauce is combined and creamy. Taste and adjust seasoning as needed. If you want your pasta to cook more or the sauce to thicken, you can turn your instant pot to sauté for a couple of minutes.
3. Serve and Enjoy. Enjoy as is or top with some toasted breadcrumbs.