Heat oven to 325; butter the bottom and sides of a 9 x 5 –inch loaf pan with butter.
Put ¼ cup sugar in a bowl; add the lemon zest and ginger and massage together
Beat the 2 sticks butter in a mixer on medium-high speed for 1 minute. Add the ginger-lemon sugar and beat for a few seconds before adding the remaining 1 cup sugar; beat 2 minutes, until lightened and fluffy.
Lower the mixer speed and drizzle in the eggs and salt; beat on medium-high speed for 2 more minutes – the mixture might look curdled but don’t worry. Slow the mixer to stir, scrape down the sides of the bowl and add half the flour; mix 15 seconds before adding the remaining flour. Mix just until there’s no more flour visible.
Scrape the batter into the prepared loaf pan. Bake 1 hour; insert a toothpick or skewer into the middle of the cake. If wet crumbs cling to the skewer, bake an additional 5 to 10 minutes.
Cool the cake in the pan on a rack 15 minutes before carefully loosening the sides with a knife. Turn the cake out onto the rack to cool completely.