Cook noodles according to box instructions. Drain well.
In large skillet over medium heat brown sausage. Add onion and cook additional 2.-3 minutes or until onion is semi-soft. Reduce heat to medium low. Add garlic, oregano. basil and spinach and cook just until spinach starts to wilt; approximately 2 minutes. Remove from heat and allow to cool for 5 minutes.
Add 2/3 cup of each cheese to the pan (reserving 1/3 of each cheese for the top). Gently fold to combine. Scoop sausage/spinach mixture into the shell. Sprinkle the rest of the cheese over the top.
Bake at 350 degrees for 25-30 minutes or until the cheese is melted.