01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Slice the bread in half horizontally and place both halves, cut side facing up, on the prepared baking sheet.
03 - In a bowl, combine softened butter, minced garlic, parsley, salt, pepper, and Parmesan cheese if using; mix until smooth.
04 - Evenly spread the garlic butter mixture over the cut sides of both bread halves.
05 - Bake for 12 to 15 minutes until the edges turn golden and butter is bubbling. Optionally, broil for 1 to 2 minutes for enhanced crispiness.
06 - Cut into 8 slices and serve warm.