01 - Set oven temperature to 350°F to ensure proper baking conditions.
02 - Cut a circular section from the top of the bread loaf and scoop out the center, maintaining a 3/4-inch thick shell. Preserve the removed bread pieces for dipping.
03 - Combine cream cheese, sour cream, mayonnaise, mozzarella, and Parmesan in a large mixing bowl. Beat until completely smooth and uniform.
04 - Fold in spinach, artichoke hearts, garlic, salt, black pepper, and red pepper flakes until evenly distributed throughout the cheese mixture.
05 - Transfer the dip mixture into the prepared bread bowl cavity. Arrange the filled bowl and reserved bread pieces on a parchment-lined baking sheet.
06 - Bake for 25-30 minutes until the dip is thoroughly heated, bubbling, and the bread exterior achieves a golden-brown color.
07 - Present the hot bread bowl dip with the reserved bread pieces and additional dippers of choice while warm.