Preheat oven to 350F (175C).

Grease a 12-cup muffin tin or line with paper liners.

In a large bowl, cream together the sugar and 1/2 cup of the butter.

Add the eggs and stir to combine it well.

In a separate small bowl, combine the food coloring and cocoa to make a paste. Add it to the butter mixture.

Sift in the salt and flour.

Combine the baking soda and vinegar in a small bowl, and fold it into the batter. Do not beat.

Add the buttermilk, 1 teaspoon of the vanilla, and water, in that order. Stir to combine.

Pour the batter into the prepared cups.   Bake for 15 to 20 minutes or until the cupcake springs back when touched.

Remove the cupcakes from the oven and allow to cool for about 10 minutes. Turn them out onto a wire rack and allow to cool completely.

Meanwhile, make the frosting by combining the remaining butter, cream cheese, remaining vanilla, and the confectioner's sugar. Blend it until smooth.

Spread the frosting onto the cool cupcakes.