Preheat the oven to 375°F (190°C). Line a baking sheet with foil for easy cleanup. This lower starting temperature helps the butter soak in without scorching the edges.

Prepare the garlic butter. In a bowl, mash the softened butter with minced garlic, parsley, Parmesan, salt, pepper, red pepper flakes, and a drizzle of olive oil. If using lemon zest, add a pinch to lift the flavors.

Slice the bread. Cut the loaf in half lengthwise to create two long slabs. For extra-crispy surfaces, you can lightly score the cut sides with shallow crosshatch marks.

Spread evenly. Slather the garlic butter across both cut sides, edge to edge. Don’t leave any dry spots. A thin, even layer prevents greasy pools and ensures even browning.

First bake: 8–10 minutes. Place the bread butter-side up on the baking sheet and bake until the butter is melted and the edges start to set. The bread should still be pale at this stage.

Boost the heat to 425°F (220°C). Bake another 5–8 minutes to get golden, toasty edges. Keep an eye on it—every oven is a little different. You want crisp edges and a soft center.

Optional broil for 1–2 minutes. If you like deeper color, switch to broil at the very end. Watch closely to avoid burning the garlic.

Rest and slice. Let the bread sit for 2 minutes so the butter reabsorbs slightly. Slice into thick pieces and serve hot.