Preheat the oven to 400 degrees F.
Heat the frozen spinach in the microwave for 5 minutes. Carefully squeeze out as much water as possible and set aside.
Microwave the cream cheese for 1 minute. Combine the cream cheese, mayonnaise, sour cream, cayenne, and garlic powder in a large bowl, and blend together well. Add the spinach, bacon, artichoke hearts, and both cheeses. Stir all the ingredients together until everything is well combined.
Spread the mixture out in a pie or tart plate or in a small casserole dish. Bake for 30 minutes, or until bubbling and slightly browned on top.
Serve hot with crackers, pita crisps, or vegetable sticks, or inside a hollowed-out sourdough bread with the cubed bread on the side.
Serving idea: Divide the mixture among smaller baking dishes or ramekins before baking it. Place the dishes of the cooked dip in different areas of the house for your party.
Shopping tip: Look in the cheese section at the grocery store for an 8-ounce bag of shredded cheese called "Italian." This blend is made of 1 cup of Parmesan and 1 cup of mozzarella cheese -- exactly what this recipe calls for.
Reprinted with permission from Savory Sweet Life by Alice Currah, William Morrow Cookbooks copyright (c) 2012