Combine cheeses in a bowl; set aside.
Whisk together eggs and next 6 ingredients in a large bowl. Stir in pasta and 3 cups cheese mixture. Pour mixture into a lightly greased 3-quart slow cooker; sprinkle with 3/4 cup cheese mixture.
Cover and cook on LOW 4 hours. Sprinkle servings evenly with remaining cheese mixture.
No Precook: The best part of this simple recipe is that you don't have to precook the pasta!