I used 2 1/4 cups of All-purpose flour for this one, and decided to substitute the sugar substitution with (you guess it) granulated white sugar, and finally, replaced the cream of tartar with 1 1/2 teaspoons of vinegar. It's rather dense, and tends to go well with coffee or tea. The cinnamon and chocolate did actually come together well in the end. The recipe is however flawed, as there is no indication of where the flour mixture is to be added (I added it along with the cold water/vanilla). Of course, no cake is complete without icing-- so I used a maple-syrup-meringue one for sandwiching and covering. Very good indeed.