Pre-heat the oven to 400 degree F. Using a fork, pierce the potatoes all around and place on a foil lined baking sheet. Bake for 50-60 minutes or until the potatoes are very tender in the center.
Once out of the oven, let the potatoes cool until you can handle them. Scoop the potatoes out of the skins and place into a potato ricer (THIS thing). If you don't have a ricer, then mash the potatoes with a fork until well combined and broken down. Let sit to cool.
In a medium pot, boil water. Place the spinach into boil for 3 minutes. Drain and place the spinach in a food processor or high speed blender and blend until pureed. If needed, add a splash of water in to help the spinach blend.
Once the potatoes are completely cooled, pour half of the pureed spinach onto the riced potatoes. Pour the flour and all of the salt on top of the spinach. Using a fork or your hands, mix it all together. Add in a bit more spinach, a few tablespoons at a time, until it is all added. The finished dough should resemble cookie dough that's just slightly sticky but easy to handle. If it's too sticky, add a bit more flour.
Once fully combined, roll the dough into a ball and cut it into eight even pieces. Roll each piece into a long log that's about 1/2 an inch thick. Cut the gnocchi into 1 inch pieces. Gently toss each piece into flour to ensure that it's dry and not sticky at any edges. Continue until you've cut out pieces from all of the dough.
Optional: using a gnocchi board or fork, press grooves into each piece of gnocchi.
The gnocchi can be stored in the fridge for 3 days, the freeze for a few weeks, or cooked right away.
To cook the gnocchi:
Heat a pot of salted water to a boil. Add in the gnocchi and let cook for a couple minutes. Once the gnocchi floats to the surface of the water, let it boil for 30 more seconds and then remove it from the water using a slotted spoon.
Toss in your favorite sauce and ENJOY! For spinach gnocchi, I really like to eat it with some simple tomato sauce and a bit of vegan parmesan cheese!! YUM!