Spread the garlic butter on both halves of the bread, coating the whole area (put a bit more in the middle so melting butter soaks the bread but doesn’t drip too much from the edges).
Put the bread on a grid, and put a baking tray under (there should be something to catch the dripping butter, otherwise it’ll burn on the bottom of the oven).
Bake for 10–20 minutes, until golden. (If the bread was just baked and still hot, 7–10 minutes should be enough.)
Notes & tips
The easiest way to peel garlic is to smash it: put a clove of garlic on a cutting board, put your chef’s knife on top of it so the blade side lays on the clove, and hit the side of the knife with your hand. Now you could peel the clove.