1/3 cup Grappa
1/2 to 1 teaspoon crushed red pepper flakes
2 tablespoons butter
2 tablespoon olive oil
1/4 cup finely chopped shallots
3 cups Italian peeled tomatoes with their juice, chopped
Coarse or kosher salt
1/2 cup heavy cream
1 pound penne pasta
1/2 cup freshly grated Parmigiano-Reggiano
Stir together the Grappa and red pepper flakes. Let stand while you make the sauce.
In a large saucepan, melt the butter with the olive oil over medium heat. Add the shallots and cook, stirring, until softened but not browned, about 3 minutes.
Stir in the tomatoes and salt to taste. Bring to a simmer and cook, stirring occasionally, until the sauce is thickened, about 15 minutes. Stir in the cream and cook 1 minute more. Strain the Grappa and discard the red pepper. Add the Grappa to the sauce. Simmer 2 minutes, but do not let the Grappa evaporate completely.
Meanwhile, cook the pasta in boiling salted water until the pasta is almost done. Drain and add it to the sauce. Cook and stir until the pasta is tender. Stir in the cheese and serve hot.