From the Cook's Illustrated Website: Be careful not to overbeat the butter-sugar mixture, especially on a hot day -- you could rupture the air cells and cause the batter to be heavy. It's important to beat in the eggs very slowly. If you don't think you can pace yourself, set a timer or watch the clock. When you are folding in the flour, fold up from the very bottom of the bowl, otherwise some of the batter will have little flour in it, and this will either rise to the surface, never cooking through, or settle in hard, dense streaks near the bottom of the cake. You may double the recipe and bake the cake in a large nonstick bundt pan (14 cup capacity); the baking time remains the same. The recipe also makes four miniature pound cakes; use four two-cup pans and reduce baking time to 40 minutes. Though best when freshly baked, the cake will keep reasonably well for 4 to 5 days.