For making the cake:-
1)Preheat oven to 350ªF.
In a large bowl, sift or whisk together flour, salt, baking powder, baking soda, sugar and cocoa.
Add 1 cup and 2 tbsp of water and 1 cup and 2 tbsp of canola oil. Mix for 1 minute.
Add eggs, 3/4 cup of water and vanilla.
Mix 5 - 6 mins with a whisk, 3 - 4 mins with a hand mixer, or 2 mins with a KitchenAid mixer.
Pour into three 10" cake pans, bake at 350ªF for 25 - 35 mins (adjust for convection); test by placing and removing a toothpick through the center at 25 mins.
When toothpick comes out clean, loosen from pans and then put back in the pans.
Let cakes cool for 15 mins. Keep in the pans, wrap in foil, and put in the freezer for at least 2 hours.
Frosting instructions:- This part is a little harder as it is really done to taste.
Put powdered sugar and 3/4 cup cocoa into a food processor. Pulse until blended.
Drizzle in, until about the consistency of firm butter, several tbsp of flavoring liquid (water if you aren`t looking for flavor beyond the cocoa and butter).
:- Do not put in too much liquid, but if you do, add cocoa or sugar. Taste.
When the flavor and consistency is right, add 1 1/2 cup of butter (firm, not cold and not too soft).
:- A good rule of thumb is that both the butter and the sugar mixture should be slightly firmer than you would want it to be to spread it, since the mixing action of the food processor will warm it slightly.
Pulse until blended.
Assembling the cake:-
1)Remove the cakes from the freezer and from their pans.
Stack, frosting each layer as you go.
Let sit for an hour before serving.