Preheat the oven to 350 degrees Fahrenheit. Line a muffin tin with paper liners.
In a large bowl, combine the flour, sugars, cocoa powder, baking soda, baking powder, soda, and salt. Whisk them together, and set aside.
In another bowl add the milk, oil, eggs, and vanilla extract and whisk them together till smooth.
Add the wet ingredients to the dry ingredients and mix until they are well combined. Make sure to scrape the bottom and sides of the bowl with a rubber spatula.
Add the hot water and mix until everything is just blended. (It will be very thin)
Pour the batter evenly into the prepared muffin tins, about 2/3 full each.
Bake for about 18-22 minutes, or until an inserted toothpick comes out with a few soft crumbs.
Remove the pan from the oven and allow the cupcakes to cool in the pan for a few minutes. Then transfer them to a cooling rack to cool completely.