In a large bowl, mix together the fine semolina flour, finely grated Parmesan cheese, and a pinch of salt until combined.
Turn the mixture out onto a clean work surface, such as your countertop or a large cutting board. Shape it into a mound and make a well in the center. Add the ricotta to the well.
Pour about one-third of the water into the well with the ricotta. Use a fork to begin pulling the flour into the center. Add more water a little at a time, only as needed, until the dough starts to come together. Once most of the flour is incorporated, use a bench scraper to cut and gather it into a shaggy, coarse dough. It will look dry at first — that’s normal.
Knead the dough on a lightly floured surface for 8–10 minutes, until smooth and elastic. The dough should not feel sticky.
Wrap the dough in plastic wrap and let it rest at room temperature for 30 minutes.
Cut off a small piece of dough, keeping the rest wrapped so it doesn’t dry out. Roll the piece into a thin log, about 3/8 inch in diameter — roughly the width of your finger.
Cut the log into small pieces about ½ inch long. Using a cavatelli board, fork, or machine, roll each piece into cavatelli. Place the shaped pasta on a tray dusted with semolina.
At this stage, you can cook the pasta right away, refrigerate the shaped cavatelli for a few hours, or freeze them in a single layer for later. If cooking immediately, let the pasta sit out briefly while you bring a large pot of salted water to a boil.
Add the cavatelli to the boiling water. Fresh pasta will cook in 2–3 minutes, while frozen pasta will take 4–5 minutes. The pasta is ready when it floats to the surface and is al dente. Drain and serve with your favorite sauce.