In a skillet, saute onions in olive oil for about 5 minutes. Add garlic and saute for a few more.
When done, put in the slow cooker.
Add a bit more olive oil if needed and brown the turkey meat. Drain and add to crock pot.
Add sauce, tomatoes, and seasonings.
Cook for 4 hours on high.
About an hour before finishing, boil water and cook the pasta until al dente (about 8-10 minutes). Drain and set aside.
About 30 minutes before finishing, add the spinach. I take about four big handfuls, adding them one at a time and waiting until it's wilted before adding more.
Then, add the pasta and cheeses.
Add that last 1/2 cup of mozzarella to top and serve when melted.