Pound cake got its name from the original formulation: a pound each of sugar, flour, butter and eggs. Just the thought of it is enough to raise your cholesterol. Our version calls for half whole-wheat flour, less sugar, a modest amount of butter and loses quite a few egg yolks. To keep it rich we moisten the cake with reduced-fat cream cheese and buttermilk. It is every bit as delicious as the original, with only a third of the calories and fat.