This marble pound cake recipe is perfect for anyone who loves a dense and buttery cake. This cake is made with all-purpose flour, baking powder, salt, unsalted butter, granulated sugar, eggs, vanilla extract, milk, and cocoa powder. The cake batter is divided into two parts, and one part is mixed with cocoa powder to create the chocolate batter. The two batters are then swirled together to create the marble effect. This cake is moist, tender, and has a beautiful swirl pattern. It's perfect for any occasion and is sure to satisfy your sweet tooth.