Just follow this recipe! It is a copycat recipe for the Starbucks' Iced Lemon Loaf. On their website, you will find the ingredients though most of them are uncommon. It stated there that they use unsalted butter and buttermilk (though we used sour cream, feel free to substitute). For a more similar taste, add in about half a teaspoon of lemon extract as they don't use the fresh citrus as we do in this version.