For the filling, soak the porcini mushrooms in approx. 150 ml of hot water for approx. 10 minutes, then remove and cut into cubes. Do not pour away the soaking water.
Briefly roast the hazelnuts dry, then let them cool. Finely dice the shallots and sauté in the butter, add the porcini mushrooms and sauté briefly.
Deglaze with the white wine, add the soaking water of the mushrooms and let it boil down, the mixture should no longer be liquid, then season with salt, honey and pepper. Possibly add more honey to taste. Let the mixture cool down.
Mix the porcini mushroom mixture with the hazelnuts, ricotta and egg yolk and season again with salt, pepper and nutmeg. Let the whole measure cool down, put in a piping bag and put in a cool place.
Knead pasta flour, eggs, water, salt and oil into a smooth, non-sticky dough (preferably in a food processor), if the dough sticks, knead in a little more pasta flour.
Let the dough rest for 30 minutes in a bowl covered with a clean kitchen towel. Then put the dough in a bag so that it doesn't dry out.
It is best to use a pasta machine to gradually roll out the pasta dough into sheets that are not too thin (with my pasta machine, thickness 6 of 9 is sufficient).
Unfold the plate and use the piping bag to spread the filling up to halfway (maximum one teaspoon every 2 cm). Fold the remaining dough over it and cut out round shapes.
Press the edges together well. Put the remaining batter back into the bag and shape more ravioli.
Place the filled noodles on a baking sheet lined with baking paper and sprinkled with pasta flour, so that they come off better afterwards and do not stick.
If the pasta is not to be cooked directly, cover the tray with a clean kitchen towel.
Bring the salt water to the boil in a large saucepan. When the water boils, add the pasta and turn the temperature down.
The water should only simmer, no longer boil, otherwise the noodles will rise. Cook the pasta for approx. 5 minutes (depending on size), when they come to the surface, they are done.