01 - Set oven temperature to 375°F.
02 - In a large mixing bowl, blend cream cheese, sour cream, and mayonnaise until smooth and creamy.
03 - Stir in mozzarella, Parmesan, garlic, salt, black pepper, and red pepper flakes if desired.
04 - Fold in chopped spinach and artichoke hearts evenly throughout the mixture.
05 - Transfer mixture into a medium oven-safe baking dish, spreading it uniformly.
06 - Bake for 20 to 25 minutes until hot, bubbling, and lightly golden on top.
07 - Arrange baguette slices on a baking sheet and brush both sides lightly with olive oil.
08 - Toast slices in the oven for 7 to 10 minutes, turning once, until crisp and golden.
09 - Serve hot dip immediately alongside toasted baguette slices.