Best Answer: A Red velvet cake is a type of rich and sweet cake, with a distinctive dark red to bright red or red-brown color. Common ingredients include buttermilk, butter, flour, cocoa powder, and often either beets, or red food coloring.It is most popular in the Southern United States, though known in other regions.The most typical frosting for a red velvet cake is a butter roux icing also known as a cooked flour frosting.ommon ingredients include buttermilk, butter, flour, cocoa powder, and often either beets, or red food coloring. It is most popular in the Southern United States, though known in other regions. The most typical frosting for a red velvet cake is a butter roux icing also known as a cooked flour frosting.