1. Bring a large pot of salted water to a boil. Cook pasta until al dente. Drain, lightly oil and set aside.
2. In a medium saucepan, sauté the sausage in Bertolli® Extra Light in Taste Olive Oil, crumbling with a wooden spoon, until no longer pink.
3. Add onion and garlic and continue sautéing for another 4 minutes until the sausage is cooked through.
4. Add marinara sauce to the sausage mixture and set aside.
5. In a medium bowl, blend ricotta cheese, egg, ¼ cup of the KRAFT Grated Parmesan Cheese and the chopped spinach; set aside.
6. Coat a 9x13 inch baking dish with olive oil and spread 1 cup of the sauce mixture on the bottom.
7. Top with 3 lasagna noodles. Spread 1/4 of the ricotta cheese mixture on the noodles and layer on 1 cup of the sauce mixture. Sprinkle 1/2 cup mozzarella cheese over this. Repeat this process three more times, starting with the noodles and finish with the remaining 1/4 cup of KRAFT Grated Parmesan cheese. Sprinkle with oregano.
8. Preheat oven to 350°F and bake for 45 minutes until hot and bubbly.
9. Let stand 10 minutes before cutting.