This lemon marble cake is a refreshing twist on the classic recipe. To make this cake, you will need all-purpose flour, baking powder, salt, unsalted butter, granulated sugar, eggs, vanilla extract, milk, lemon zest, and lemon juice. The cake batter is divided into two parts, and one part is mixed with lemon zest and juice to create the lemon batter. The two batters are then swirled together to create the marble effect. This cake is perfect for spring or summer and is sure to brighten up any table.