Add spinach (frozen or fresh), cream cheese, mayonnaise, sour cream, Parmesan cheese, chopped artichokes and garlic powder (optional) to your crockpot set to high. Cook for 1 hour, stirring half way through and more as needed to break up the frozen block of spinach and cream cheese.
Dip is ready when all ingredients have combined together evenly and are piping hot. About 1 hour or less if using thawed or fresh spinach. Serve hot with tortilla chips or crust bread.
To prepare on the stovetop: combine all ingredients in a pot over medium-high heat. Cook and stir frequently for about 10-15 minutes or until all ingredients are evenly combined into a creamy texture.