Cook and drain the egg noodles according to package directions. Add 1 tablespoon of the butter, toss to coat and season lightly with salt and freshly ground black pepper. Set aside.
Heat the remaining 4 tablespoons of butter in a large skillet over medium-high heat until it begins to foam.
Add the shallot and sauté until softened, 2 to 3 minutes. Add the sage and cook, stirring constantly, until the butter is lightly browned and has developed a nutty aroma.
Don't leave unattended as the butter can go from browned to burned very quickly.
Stir in the pumpkin puré and cream until smooth and well blended. Add the noodles and combine well. Season to taste with salt, pepper, and nutmeg.