Cooking your own pasta sauce? Get it started if so, using your favorite recipe. Using a jarred version? Warm it up in a small saucepan over low heat.
Boil the spaghetti according to package directions in a large pot.
Preheat the oven to 350 degrees F.
Divide out 1 cup of cheese blend and ¼ cup of Parmesan in a bowl and set aside. Pour the rest of the Parmesan in with the bigger portion of cheese blend.
In a medium sized pot, melt the butter over medium heat.
Measure out the milk and heavy cream so it’s ready to go.
Once the butter is melted, whisk in the flour, keeping the motion going so that there are no lumps.
When the flour and butter are thoroughly combined, slowly pour in the milk. Slowly add in the cream, still whisking!
Bring the heat up to medium high, and continue whisking, but you can be a bit less constant.
Add the dash of nutmeg at this point, and salt and pepper if desired.
Slowly begin adding the larger portion of the cheese blend to the cream mixture. Keep whisking til the cheese has melted and turn off the heat.
At this point, drain the spaghetti but reserve 1 cup of pasta water.
Remove 1 cup of cheese sauce from the rest and set aside.
Mix the spaghetti and remaining cheese sauce in the large spaghetti boiling pot. Combine thoroughly, using the pasta water to thin the sauce as needed so every strand is coated.
Dump the spaghetti-cheese mixture into an ungreased, locked 8″ springform pan. Use a large spoon to even out the top.
Bake for 20 minutes.
Remove from oven and spread remaining cheese sauce on top. Top with remaining Parmesan and cheese blend.
Bake for 10 more minutes.
Remove from oven and let rest for 10 minutes before running a knife around the edge to loosen the baked on cheese topping from the edges.
Unlock the springform pan and gently remove the outer part of the pan from the pie. Use the knife to coax loose strands as needed.
To serve, put as much pasta sauce as you desire on a plate, then use a large, sharp knife and pie server to place a piece of pie on the sauced plate. Garnish as desired.