01 - Set oven temperature to 375°F (190°C).
02 - In a large mixing bowl, blend softened cream cheese, sour cream, and mayonnaise until smooth and creamy.
03 - Stir in grated mozzarella, Parmesan, minced garlic, salt, black pepper, and crushed red pepper flakes if using.
04 - Gently fold in the chopped spinach and artichoke hearts until mixture is evenly combined.
05 - Transfer the mixture to a medium-sized oven-safe baking dish and spread evenly.
06 - Bake for 20 to 25 minutes until the dip is hot, bubbling, and golden on top.
07 - Arrange baguette slices on a baking sheet and brush both sides lightly with olive oil.
08 - Toast the baguette slices in the oven for 7 to 10 minutes, turning once midway, until golden and crisp.
09 - Serve the hot dip immediately accompanied by the toasted baguette slices.