For sauce, heat oil in a medium saucepan. Cook onion and garlic in hot oil until onion is tender, stirring occasionally. Carefully stir in undrained tomatoes, tomato paste, basil, sugar, salt, and pepper. Bring to boiling; reduce heat. Simmer, uncovered, about 5 minutes or until sauce is desired consistency, stirring occasionally.
Meanwhile, cook pasta according to package directions; drain. Rinse with cold water; drain well.
For filling, drain thawed spinach well, pressing out excess liquid. In a medium bowl stir together ricotta cheese, mozzarella cheese, Parmesan cheese, and basil. Add spinach and egg white, stirring to combine.
Preheat oven to 350 degree F. To assemble, evenly spread about 1/4 cup filling on each noodle. Roll up from one end. Place two rolls, seam side down, into each of four individual casseroles. Top each serving with sauce. Bake casseroles, covered, for 25 minutes or until heated through. Makes 4 servings.