Heat oven to 350°F and line a large baking sheet with foil.
Slice the loaf in-half lengthwise, and place each half cut-side up on the prepared baking sheet.
1 16 ounce loaf of Italian or French bread
In a small saucepan set over LOW heat, combine butter, garlic and crushed red pepper flakes. Bring the mixture to a low boil and boil for 1 minute. Do NOT allow the garlic to brown. Remove from heat.
4 cloves garlic, 16 tablespoons unsalted butter, ¼ teaspoon crushed red pepper flakes
Pour the butter through a mesh strainer and into a heatproof bowl. Add 1-tablespoon parsley and mix well.
1 tablespoon minced fresh parsley
Spread or brush all except 4 tablespoons butter mixture over the bread and sprinkle with salt.
1 teaspoon coarse or flaked sea salt
Bake the bread at 350°F, on the middle rack of the oven, for 10 minutes.
Remove the bread from the oven and set the temperature to BROIL. If using Parmesan cheese, sprinkle it onto the bread.
¼ cup freshly grated Parmesan cheese
Return the bread to the oven and broil 1-2 minutes or until the bread is toasty and golden and the cheese bubbles slightly. Watch closely so the bread doesn’t burn.
Remove from the oven and sprinkle with the remaining ½ tablespoon of parsley. Allow the bread to cool 1-minute before slicing.
Use leftover butter mixture for a dipping sauce, if desired. Serve immediately.