01 - Preheat the oven to 375°F. Line a baking sheet with parchment paper.
02 - Cut the baguette in half lengthwise and place both halves cut side up on the prepared baking sheet.
03 - Combine softened butter, minced garlic, chopped parsley, salt, and black pepper in a small bowl until well blended.
04 - Evenly spread the garlic butter mixture over the cut sides of the bread.
05 - Sprinkle mozzarella, cheddar, and Parmesan cheeses uniformly over both bread halves.
06 - Bake in the preheated oven for 15 to 20 minutes until the cheese melts, bubbles, and the edges turn golden brown.
07 - Broil for an additional 2 minutes for extra crispiness, monitoring closely to avoid burning.
08 - Remove from the oven, let cool briefly, then slice and serve warm.