When measuring flour, we spoon it into a dry measurement cup and level off the excess. Scooping directly from the bag compacts the flour, resulting in dry baked goods. The butter, eggs and buttermilk should be at room temperature so that the batter mixes and cooks evenly. Be sure to beat the butter and sugar for the full 4 minutes specified to create volume and lightness, which gives the cake height and a tender crumb. Once the flour is added, mix only until the ingredients are just combined and no streaks of flour remain; overmixing will result in a tough cake.