01 - Preheat the oven to 400°F and line a baking sheet with parchment paper.
02 - Slice the baguette lengthwise in half, then cut each half into 4 pieces to yield 8 slices total.
03 - Combine softened butter, minced garlic, parsley, chives if using, salt, and black pepper in a bowl until thoroughly mixed.
04 - Spread the prepared garlic butter evenly over the cut sides of each bread slice.
05 - Sprinkle shredded mozzarella evenly over each slice, then top with grated Parmesan cheese.
06 - Place the bread slices cut side up on the lined baking sheet.
07 - Bake for 10 to 12 minutes until cheese is melted and lightly golden. For extra crispiness, broil for 1 to 2 minutes at the end, watching carefully.
08 - Remove from oven, allow to cool slightly, and serve warm.