This is among the most basic of batters but it still manages to yield a flavorful cake, proving that sometimes less is best (as in less fuss and less ingredients). Just butter, eggs, sugar, grated lemon zest, milk, salt, flour, and baking powder are needed for the batter, which comes together quickly with an electric mixer. Be generous when sprinkling the cake with sugar before putting in the oven to bake, for a crunchy topping.