Step 1

Preheat oven to 400°F (204°C). Line a baking sheet with parchment paper or silicone baking mat. Place both halves of bread, cut side up, on the lined baking sheet.

Step 2

Using a handheld or stand mixer fitted with a paddle attachment, beat the butter, parsley, garlic, salt, and parmesan cheese (if using) together on medium-high speed until completely combined and smooth. If your butter is soft enough, you can simply use a fork to mash it all together.

Step 3

Spread the garlic butter in an even layer on top of the slices of bread.

Step 4

Bake for 16–18 minutes, or until the edges of the bread are crispy and golden brown. Feel free to extend this time by a couple minutes for a crispier exterior.

Step 5

Let cool on the baking sheet for a few minutes until cool enough to handle, and then transfer the garlic bread to a cutting board. If using, sprinkle with crushed red pepper flakes. Using a serrated bread knife, slice the bread into pieces and serve warm.

Step 6

Cover leftover bread tightly and store at room temperature or in the refrigerator for up to 3 days.