Preheat oven to 350℉ (180℃). Grease and flour two muffin (cupcake) pans (or two 9-inch round cake pans) with baking spray. Optionally line with cupcake liners. Set aside.
In a medium bowl, combine the flour, salt, and cocoa powder, and set aside.
Cream the butter and sugar at high speed in a stand mixer (or hand mixer) until fluffy and starting to look white, about 4 minutes. Then add the sour cream and mix for a minute. Follow with the oil, and mix for another minute.
Add the eggs one at a time, beating the mixture well between each addition.
Next, pour in the buttermilk, vanilla extract, and vinegar, and mix thoroughly.
Add the red food coloring until the desired color has been reached.
Slowly add the dry ingredients to the wet. Then mix the baking soda and water and gently fold them into the cake batter, scraping down the sides of the bowl as you mix.
Divide the batter evenly by scooping it into the cupcake wells with a measuring cup. Tap the pan on the countertop to release bubbles.
Bake at 350℉ (180℃) for 25-30 minutes or until a toothpick inserted in a cupcake comes out clean.
Let the cupcakes cool in the pans for 10-15 minutes.
Once the cupcakes have completely cooled, wrap them in plastic wrap and chill them in the refrigerator for at least an hour, preferably overnight. This makes frosting them so much easier.