grease the paper as well.
place the cocoa in a medium bowl and add the hot water. whisk until smooth and let it cool to room temperature.
in the bowl of an electric mixer, combine the sugar, flour, baking soda, and salt. with the mixer on low blend to combine. add the butter and the dissolved cocoa. then raise the mixer to medium speed and beat for 2 minutes until light and fluffy.
in a medium bowl whisk together the eggs, vanilla, and cold water until combined. add this liquid to the batter in three additions scraping down the sides of the bowl between additions. divide the batter among the three pans.
bake for 