Preheat oven to 400 degrees.

Wash the potatoes thoroughly and pat dry with a paper towel. Poke each potato with a fork to allow the steam to release while baking. Arrange potatoes on a sheet pan and bake for at least 1 hour or until very soft.

As quickly as you can handle the potatoes, using a knife split each potato down the center to allow the steam to release. Moisture is the enemy of light and fluffy gnocchi. Then also as quickly as you can, pass the potatoes through a ricer and
spread evenly across a sheet pan. You do this to allow the maximum amount of moisture to be released through steam. Using a fork fluff the potatoes as the steam releases. This will allow even more steam to escape. At this point, you can let the potato rest until you are ready to make the dough up to 24 hours. If you plan to le rest overnight cover and place in refrigerator.

Sprinkle the flour and cheese evenly over the fluffed potatoes. Using a fork fluff the potatoes with the flour. Transfer potato, flour, and cheese into a large mixing bowl. Add the 4 egg yolks and mix with your hands until well combined. Once dough has begun to come together. Transfer dough to a floured work surface. Gently kneed the dough until it comes together. You do not want to over knead because that will make your gnocchi tough. If the dough is sticky add more flour a little at a time until it no longer sticks to your hands or the counter.

Using a pastry cutter slice of a piece of the dough approximately the size of your fist. Dust the dough with flour. With the palm of your hand roll the dough into a snake shaped rope. ½ inch thick. Cut the rope into ½ inch long segments.

You can stop here if you like.

If you have a gnocchi paddle you can continue to roll each piece across the paddle creating groves on the outside and a hallow center. If you do this step your gnocchi will seem lighter and hold more sauce in the groves and center.

It takes practice to get the rolling technique down but you can always eat your mistakes. The dough is very forgiving. Place the gnocchi on a floured sheet pan and cook within an hour. The gnocchi freezes well but you must first freeze them where they cannot touch each other to prevent them from sticking together. I arrange them on plates and put in freezer until hard. I then transfer the frozen gnocchi from the plates to plastic bags.