In a large bowl, add the flour. Make a well in the center and add ricotta cheese, Parmesan, eggs, and salt. Mix until combined.
Turn mixture to a well-floured board and begin gently kneading. Add more flour as necessary until dough stops sticking to your fingers. Form into a large ball.
Divide the dough into four sections. Roll each section into 1/2-inch-thick rope. Cut each rope in 1-inch pieces.
To make the ridges, roll each piece down the tines of a fork or gnocchi board.
Sprinkle gnocchi with flour as needed to prevent sticking. Spread them out and allow them rest a bit while you heat the sauce and boil the water.
Add the tomato sauce to a medium saucepan, and bring to a simmer over medium-low heat.
Bring a large pot of lightly salted water to a boil over high heat.
Gently add the gnocchi to the boiling water and cook until they float to the surface, about 2 to 3 minutes.
Remove the gnocchi with a slotted spoon and place into a large serving bowl. Spoon sauce over gnocchi and stir lightly with a wooden spoon until mixed. Serve with extra tomato sauce and grated Parmesan cheese.