Line the cupcake tins with paper liners.
Preheat oven to 350 degrees.
Mix the flour, sugar, cocoa, baking soda, baking powder and salt in a bowl.
In a separate bowl add the eggs, whole milk,water, kahlua and oil.
Add the bowl containing the eggs, whole milk, oil, and vanilla to the bowl holding the dry ingredients.
Mix all together until fully incorporated.
Beat for 3 minutes on medium.
Slowly add the boiling water starting with a small amount then pour in the remaining boiling water.
The batter may be a little runny.
Scoop batter into cupcake lined cups until 3/4s filled.
Bake at 350 degrees for 20-25 minutes.
Remove from oven and allow to cool completely.