In a stand mixer, mix all purpose flour, semolina flour, and salt. Then, add eggs and water. Add olive oil if desired. With a dough hook on low speed, knead for 5-10 minutes on low speed or until the dough is smooth. If the dough feels dry, add a tablespoon of water at a time.
Cover the dough with plastic wrap and let it rest for 30 minutes at room temperature.
On a floured surface, cut the dough into 8 pieces. Take a portion and flatten it by hand. Using a pasta roller, pass it through the #2 setting.
Fold the dough into thirds and pass it through #2 again. Then, feed it through settings #3 and #4 once and twice on #5. Generously dust with flour and repeat with remaining dough.
Switch to the fettuccini cutter or your favorite noodle shape and on setting #2, pass the pasta sheets through to cut the the noodles. Repeat with remaining dough. Dust with more flour as needed.