It's so easy to turn this into a lemon pound cake without making any adjustments to the recipe. Simply replace the orange juice with lemon juice and replace the orange zest with lemon zest. For a bit of extra flavouring, add a dash of vanilla extract or rum extract. You can also infuse a pound cake with 1 - 2 tablespoon of liquors like limoncello (lemon-flavoured liquor), brandy, vodka, or amaretto.