1. Position a rack in the lower third of the oven. Preheat the oven to 350 degrees.
2. In a large mixing bowl, mix the flour, cocoa powder, sugar, baking soda, and salt together thoroughly. Add the butter, eggs, and vanilla and beat on medium speed for one minute.
3. Add half of the water and beat for 20 seconds. Scrape the sides of the bowl and add the remaining water. Beat for 20-30 seconds until the batter is smooth. The batter will be thin enough to pour.
4. Divide it evenly among the lined cups. Bake 18-22 minutes (rotating the pan from front to back half-way through the baking time), just until a toothpick inserted into a few of the cupcakes comes out clean. Set the pan on a rack to cool. Frost the cupcakes when they are completely cool. Store and serve at room temperature.