Line slow cooker with sliced cheese, artichoke hearts, spinach (thawed/drained), alfredo and mayo. Cook on med/high for 4 hours, stirring every 30-45 minutes until everything is melted. Can top with Parmesan/Shredded Provolone/Shredded Mozzarella.
In a medium saucepan add butter, heavy whipping cream, and cream cheese. Cook over medium heat and whisk until melted. Add the minced garlic, garlic powder, italian seasoning, salt and pepper. Continue to whisk until smooth. Add the grated parmesan cheese. Bring to a simmer and continue to cook for about 3-5 minutes or until it starts to thicken. Toss it with your favorite pasta!