Uncover the secret to the perfect red velvet cake with this recipe. The key lies in the combination of buttermilk, vinegar, and cocoa powder, which gives the cake its signature tangy and slightly chocolatey flavor. The addition of a hint of espresso powder enhances the richness of the cake. Frosted with a smooth cream cheese frosting and adorned with red velvet cake crumbs, this cake is a showstopper that will leave everyone wanting more.