Even with such ingredients, however, these traditional cakes weren't as colorful as modern red velvet. The once subtly red cake went on a long journey to become its current saturated self.

Preheat your oven to 350°F (175°C). Grease and lightly flour two 9-inch round cake pans to prevent sticking. In a medium bowl, whisk together the flour, baking soda, and cocoa powder. Set this ...