Prepare the pasta dough following the recipe linked above.
cook the spinach in boiling water until tender. It should take only a few minutes.
Drain the spinach and try to squeeze as much water out as you can.
Chop the spinach and add to a large bowl, with the ricotta cheese, egg, Parmesan cheese, nutmeg and a bit of salt. Mix well.
Divide the pasta dough in two parts. Keep the half that you are not using in the plastic wrap.
Roll the dough in a thin layer, about 1/8 of an inch, or as thin as you can. When you roll, always make sure the pasta doesn't stick to the counter. Move and rotate the dough as necessary.
Cut the dough halfway. Using your cutter and starting from one end, measure and mark (do not cut) the distance between the ravioli, on half of the dough only. You should be able to get 20-22 ravioli. Place about one teaspoon of filling on the pasta in the middle of each of the ravioli At this point you should used only half of the ricotta/spinach filling.
Place the other half of pasta, and press down around the filling with your fingers. You want to get most of the air out so that your ravioli will seal nicely.
Cut the ravioli using your cutter. Set aside on parchment paper lightly floured. Make sure the ravioli don't touch each other or they will stick together.