Step 1

Preheat the oven to 350°F and line a baking sheet with parchment paper. Arrange an oven rack in the top third of the oven.

Step 2

In a small bowl, stir together the softened butter, parsley, garlic, and salt.

Step 3

Use a serrated knife to slice the bread in half lengthwise. Slather the cut sides with the garlic butter. Place the bread, cut side up, on the baking sheet.

Step 4

Place on the high oven rack and bake for 8 minutes, then broil for 2 to 5 minutes, or until the bread is golden brown around the edges. Sprinkle with the Parmesan, flaky sea salt, parsley, and red pepper flakes, if desired. Slice and serve hot.