Preheat the oven to 350 degrees Fahrenheit.
Butter an 18x13 baking pan. Then line the pan with parchment paper. Also, butter the parchment paper too, set aside.
In a large bowl mix the flour, cocoa powder, baking soda, baking powder, and salt. Set aside.
In another large bowl with a hand mixer beat the butter and sugar for 2 minutes. Until all is combined
Next, add in 1 egg and mix until all is incorporated.
Repeat with the last egg.
To the butter mixture add half of the dry ingredients alternating with milk.
Mix until all dry ingredients and milk are incorporated.
Now add the water a bit at a time.
Pour the cake mixture into the prepared pan and spread it evenly as possible.
Bake for 15-17 minutes or until the cake is completely baked.
Allow the cake to cool off completely before decorating.