Heat the oven to 300 degrees F. Butter and flour two 9-x-5-inch loaf pans.
Measure out 6 level tablespoons sugar into a cup or bowl.
Beat the egg whites until they begin to form peaks; then gradually beat in the
6 tablespoons sugar. Place this sort-of meringue in the refrigerator until you need
In a large bowl, cream the butter well. Gradually beat in the rest of the sugar
and the salt; then beat in the egg yolks, two at a time. Add the flour and the cream
alternately to the butter mixture, beginning and ending with the dry ingredients.
Add the mace. Whip until the batter is as light as possible, about 10 minutes at
medium speed. Then fold in the egg-white mixture and the vanilla extract. You'll
feel as if you're trying to fold egg whites into cement, but persevere. Pour
the batter into the prepared loaf pans.
Bake for 50 to 60 minutes, or just until a cake tester stuck in the middle of
the cake comes out clean.
Cool on a rack for 15 minutes; then invert onto the rack
and re-invert onto another rack so the cake will cool right side up.