- Preheat the oven to 375 °F (191 °C).
- In a gallon of salted, boiling water, cook pasta until al dente. Drain and rinse with cold water. Set aside.
- Combine ricotta, egg yolks, butter, salt, pepper, garlic, parsley, and tomato paste. Fold in cooked pasta. Set aside.
- In a spotlessly clean metal bowl, beat egg whites to stiff peaks with cream of tartar. Gently fold into pasta mixture.
- Pour into a parchment-lined high-sided roasting pan. Sprinkle with mozzarella cheese and cover with aluminum foil. Bake in the center of the oven for 15 minutes.
- Remove foil and lower temperature to 350 °F (177 °C). Bake for another 30 minutes or until browned and bubbly on top.
- Place serving portions onto plates and garnish with basil. Serve warm.