Fill a large pot up with water and bring to a boil.
Once the water has started to boil and the box of pasta, stirring so the pasta does not stick together.
Cook only for 2-3 minutes and then drain.
Pour the pasta into a slow cooker and add milk, cheddar cheeses, parmesan, and salt and pepper.
Cook on low for 1 hour, stirring occasionally.
Cut the cream cheese into cubes and stir in the cream cheese and the sour cream until cream cheese starts to melt.
Cook on low for an additional 20-30 minutes until all the cheeses have melted.
Serve as is or with bacon on top.