In a large bowl, sift together the flour, cocoa powder, powdered sugar, and salt.

Make a well in the center of the flour mixture and add in the eggs and vanilla extract. Stir together with a wooden spoon until the dough comes together. Add a little milk if the dough still seems dry.

Transfer the dough to a work surface and knead for 8-10 minutes, until the dough is smooth. (You can also knead the dough for 5 minutes on low speed in a stand mixer fitted with a dough hook.) Cover the dough with plastic wrap and refrigerate for 30 minutes.

Lightly flour a baking sheet and set aside. Divide the dough into quarters for the easiest handling, and work with one portion at a time.

For best results, use a pasta machine to roll the dough because you need to get it VERY thin. By hand, roll the dough on a floured surface as thinly as you possibly can. This will take some time but keep at it. Allow the dough to rest if it keeps springing back while rolling.

Cut the dough into 1/2-inch (2cm) wide strips and place them on the prepared baking sheet while you roll and cut the remaining dough.

In a medium saucepan over low heat, combine the Nutella, heavy cream, and salt, stirring frequently, until smooth. Remove from the heat, cover to keep warm, and set aside.

Fill a large pot halfway with water and bring to a rolling boil. Cook the pasta for about 3 minutes, or until it floats to the surface of the pot. Drain and immediately toss with the sauce.

Divide the pasta among 6 plates, then garnish with raspberries, chopped hazelnuts, and a dollop of whipped cream.

This pasta is best cooked and eaten the day it is made.