Preheat oven to 350°F. Grease and line three 8-inch cake pans.
In a large bowl, whisk together flour, cocoa powder, sugar, baking soda, baking powder, and salt.
Add eggs, milk, oil, and vanilla. Mix until smooth.
Slowly pour in hot water while mixing. The batter will be thin. That’s normal.
Divide evenly between pans and bake 28–32 minutes or until a toothpick comes out clean when inserted into the center.
Let cool completely!
Once cooled, slice each layer in half horizontally so you have six thin layers.