In a large pot, bring well-salted water to a boil. Boil the pasta according to the package directions, typically about 7 minutes. Drain and set aside.
Meanwhile, in a wide-bottomed pan, heat half of the olive oil over medium heat. Sauté mushrooms until deeply browned, about 10 minutes. Remove from pan.
Add the other half of the olive oil and the asparagus to the pan and sauté until tender-crisp, about 3 to 5 minutes. Remove from pan.
Lower the heat to medium-low and melt the butter. Add the heavy cream, Parmigiano Reggiano, salt, and pepper to the pan. Gently simmer until everything is combined and slightly thickened, about 2 minutes.
Return the mushrooms and asparagus along with the pasta to the pan. Toss to combine.
When serving, top with additional Parmigiano Reggiano and freshly ground black pepper, if desired.
Notes
When reheating, you can cover with a damp paper towel and microwave in 30-second increments. However, much of the sauce will be absorbed by the pasta.
Another option is to quickly make more sauce by melting 1/2 a tablespoon of butter and adding a 1/4 cup of heavy cream and a grating of the Parmigiano Reggiano. Then, toss with the leftover pasta and salt and pepper to taste. This way will produce creamier results.