Preheat your oven to 350°F (175°C) and line a cupcake pan with paper liners.
In a large mixing bowl, sift together the flour, cocoa powder, baking soda, and salt. Whisk until combined and set aside.
In another bowl, whisk together the sugar, oil, eggs, and vanilla until the mixture is smooth and slightly frothy.
Add the red food coloring and vinegar to the wet mixture, then whisk to combine, creating a vibrant, uniform color.
Gradually pour the dry ingredients into the wet mixture, folding gently with a spatula or mixing on low speed until just combined; the batter will be smooth and slightly thick.
Pour the buttermilk into the batter and fold in thoroughly, ensuring a consistent, silky texture without overmixing.
Divide the batter evenly among the cupcake liners, filling each about two-thirds full to allow for rising.
Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean and the cupcakes spring back when lightly pressed.
Remove the cupcakes from the oven and let them cool in the pan for 5 minutes before transferring to a wire rack to cool completely.
Once cooled, frost the cupcakes with your favorite cream cheese or vanilla frosting for a classic finish.
Enjoy these vibrant, moist cupcakes with a tender crumb and a hint of cocoa that taste as good as they look.