Preheat your oven to 350°F. Line a 12 count cupcake tin with paper liners, and set aside.
In a small bowl, whisk together your flour, cocoa powder, baking powder, baking soda, and salt. Set aside.
In a separate large bowl, combine butter, oil, and sugar. Beat together using a wooden spoon or an electric mixer until relatively smooth and combined. It may be slightly grainy, but that's normal!
Add your eggs to the sugar mixture, one at a time, beating well after each addition. Add in the sour cream, vinegar, food coloring, and vanilla, and whisk to combine.
Alternate adding your dry ingredients and buttermilk to the sugar mixture. Make sure to start and end with the dry ingredients (so 3 additions of dry ingredients, and 2 additions of buttercream), and whisk between each addition until just combined. Take care not to over mix!
Divide the batter evenly into your cupcake tin. You may need to do 2 batches, so just make sure that each cup is filled no more than 2/3 of the way full.
Bake the cupcakes in the center of your preheated 350°F oven for 15 to 20 minutes, or until a tooth pick inserted into the center of a cupcake comes out clean. Cool completely before frosting!