Heat the olive oil in a large skillet over medium high heat. Add the sausage and brown, breaking up the meat into bite size pieces. Use a slotted spoon to transfer the sausage to a bowl.
Add the garlic to the same skillet, and sauté for a minute or two until tender. Stir in the spinach and cook until wilted, about 5 minutes. Add the sausage back into the pan.
Meanwhile bring a large pot of salted water to a boil. Cook the pasta until al dente. Drain the pasta and add to the sausage mixture. Stir in the cheeses, milk and parsley, and toss to coat. Adjust the seasoning with salt and pepper to taste. Dust with the Parmesan and serve.