Preheat your oven to 450°F, ensuring it's hot enough for a perfect crisp.
In a small saucepan, melt the butter over low heat.
Add the garlic, stirring occasionally, and cook for about 20 minutes until very tender.
Once the garlic mixture is tender, remove it from heat and let it cool slightly.
Mix in the parsley, lemon zest, red pepper flakes, salt, and black pepper.
Cut the baguette in half horizontally.
Generously spread the garlic mixture on each half and sprinkle with Parmesan.
Place the bread on a baking sheet and bake for 5 to 7 minutes, or until golden and crisp.