This red velvet marble cake is a stunning dessert that is perfect for any special occasion. To make this cake, you will need all-purpose flour, baking powder, salt, unsalted butter, granulated sugar, eggs, vanilla extract, milk, cocoa powder, and red food coloring. The cake batter is divided into two parts, and one part is mixed with cocoa powder and red food coloring to create the red velvet batter. The two batters are then swirled together to create the marble effect. This cake is moist, tender, and has a beautiful red and chocolate swirl pattern. It's sure to impress your guests.