This old-fashioned, moist chocolate cake has a fine grain and tender crumb. It is sensational at sea level and made-to-order for high elevations because it contains buttermilk, a favorite high-altitude ingredient that contributes moisture and tenderness as well as extra acidity to help the batter set quickly. For Valentine’s Day, bake it in heart-shaped metal cake pans (see recipe instructions). Fill the layers with your favorite raspberry jam and frost with Bittersweet Chocolate Icing (recipe follows). This recipe is written for sea level, with altitude adjustments in parentheses.