Make the pasta dough: In a large mixing bowl, combine the flour and salt.

Make a well in the center and add the eggs and olive oil. Using a fork, mix the eggs and oil with the flour until a dough forms.

Knead the dough for 5-10 minutes until smooth and elastic.

Cover with plastic wrap and let rest for 30 minutes.

Make the filling: In a large bowl, mix together the ricotta cheese, chopped spinach, parmesan cheese, egg, salt, and pepper.

Roll out the pasta dough into thin sheets using a pasta machine or a rolling pin.

Cut the pasta sheets into circles using a cookie cutter or a glass.

Place a spoonful of the ricotta and spinach filling in the center of each pasta circle.

Fold the pasta over to create a half-moon shape and press the edges to seal.

Make the sauce: In a large saucepan, heat the olive oil over medium heat.

Add the onion and garlic and sauté for 2-3 minutes until soft.

Add the crushed tomatoes, salt, and pepper and simmer for 10-15 minutes until thickened.

Cook the ravioli in a large pot of salted boiling water for 3-5 minutes until tender.

Drain and transfer to a serving plate.

Pour the tomato sauce over the ravioli and garnish with chopped fresh basil.