All-Purpose Flour: 3 cups, spooned and leveled. This provides the ideal structural framework. For a slightly more tender crumb, you can substitute half of this with cake flour.Granulated Sugar: 2 cups. Sugar does not just sweeten; it hydro-locks moisture into the crumb and creates that gorgeous, slightly crisp outer crust.Unsalted Butter: 1 cup (2 sticks), softened to room temperature. Using European-style butter with a higher fat content yields an incomparably rich, milky flavor.Large Eggs: 4 whole eggs, strictly at room temperature, to emulsify beautifully into the batter without breaking the creamed butter.Buttermilk: 1 cup, room temperature. The acidity in thick, cultured buttermilk tenderizes the gluten and reacts with the leavening agents for a plush texture. If unavailable, mix 1 cup of whole milk with 1 tablespoon of white vinegar and let it sit for 5 minutes.Pure Vanilla Extract: 1 tablespoon. Because vanilla is the star profile, avoid artificial essences and opt for pure extract or vanilla bean paste for those beautiful aromatic flecks.Baking Powder: 1 teaspoon to give the dense batter a gentle, elegant lift.Salt: 0.5 teaspoons of fine sea salt to cut through the sweetness and elevate the buttery notes.