Preheat your oven to 350°F and line a 12-cup muffin tin with cupcake liners.
In a bowl, whisk together flour, cocoa powder, baking soda, and salt.
In another bowl, beat the butter and sugar until fluffy. Add eggs one at a time, then stir in vanilla.
Mix in the dry ingredients, alternating with buttermilk, until smooth.
Stir in the red food coloring and vinegar until the batter is evenly red.
Divide batter evenly among cupcake liners, filling each about two-thirds full.
Bake for 18–20 minutes or until a toothpick comes out clean.
Cool completely, then top with cream cheese frosting and swirl generously.