TO MAKE THE PASTA DOUGH: In a large bowl, combine the cassava flour with the eggs, olive oil, and salt. Stir to combine, eventually switching to your hands to combine/knead the dough. The dough should feel soft but not sticky. Cover and let rest for 20 minutes.
TO MAKE THE CAULIFLOWER: While the dough is resting, cook the cauliflower. Preheat the oven to 425˚F. Chop the cauliflower into bite-sized pieces. Place in a roasting pan and toss with the olive oil, salt, and pepper. Roast until the cauliflower is tender and browning, 25 to 30 minutes.
TO MAKE THE PESTO: Combine the ingredients for the pesto in a food processor or blender. Puree, adding water as needed, to thin the sauce.
TO MAKE THE PASTA: Once the dough has rested, bring a pot of salted water to a boil. Divide into two smaller pieces. Use the cassava flour to create a floured surface. Roll the dough into a thin rectangle and using a knife or pizza cutter, cut the dough into ⅛” wide strips. Place in the boiling water and cook for 3 to 4 minutes. Scoop out the pasta into a strainer and repeat with the second ball of pasta dough.
Once the pasta is done, drain the water from the pan, reserving about 1 cup of the water. Place the pasta in the pan and add the pesto and roasted cauliflower. Toss until everything is combined. Divide into bowls and top with basil and parmesan (if using).