1. Preheat your oven to 350°F (175°C). Lightly grease a 9-inch baking dish or similar-sized casserole dish.
2. If using fresh spinach, sauté it in a pan over medium heat with a teaspoon of olive oil and a pinch of salt until wilted, about 3-4 minutes. Drain any excess liquid and set aside. If using frozen spinach, ensure it’s thoroughly thawed and squeezed dry to avoid a watery dip.
3. In a large mixing bowl, combine the softened cream cheese, sour cream, and mayonnaise. Use a hand mixer or sturdy whisk to blend until smooth and creamy.
4. Add the chopped onion, minced garlic, Worcestershire sauce, salt, pepper, and red pepper flakes if using. Stir to combine evenly.
5. Fold in the cooked spinach, mozzarella, and half of the Parmesan cheese. Mix gently until incorporated, being careful not to overwork the mixture.
6. Transfer the mixture to your prepared baking dish and spread evenly.
7. Sprinkle the remaining Parmesan cheese over the top for a golden, flavorful crust.
8. Bake in the preheated oven for 25-30 minutes, or until the edges are bubbly and the top is golden brown.
9. Remove from the oven and let it cool slightly before serving. This helps the dip set and makes it easier to scoop.

One of Mama Lou’s little secrets was to let the dip rest a bit before serving. She said it gave the flavors time to mingle and made every bite more delicious. Ouma and I always followed that advice, and it never failed. The aroma alone was enough to gather the whole family around the table, eagerly grabbing slices of toasted baguette or crunchy crackers to scoop up the creamy goodness.