Margaret Fox's Amazon Chocolate Cake

The site had ahttp://food52.com/blog/9470-dutch-process-vs-natural-cocoa-powder-when-to-use-themn article about this topic. perhaps it would help:

"There are exceptions to each, of course. And according to Fine Cooking magazine, “You can substitute natural cocoa powder for Dutch-process in most recipes (though not vice versa). Flavor and texture can be affected, but generally only in recipes calling for 3/4 cup (75 g) or more.” However when a batter-based recipe calls for natural cocoa powder, do not use Dutch-process cocoa powder. But I always advise folks to follow what the recipe says. For sauces and ice creams, they can be swapped out. For cakes and cookies, I don’t recommend it, as your results may not be the same if you make substitutions.

Remember: As in any recipe, if you vary ingredients or make substitutions from what is written, results will likely not be the same.

If a recipe calls for either, the main different is that Dutch-process cocoa will give a darker color and a more complex flavor whereas natural cocoa powder tends to be fruitier tasting and lighter in color."
Above and more is from:
http://www.davidlebovitz.com/2010/02/cocoa-powder-faq-dutch-process-v/

1 1/2
cup all-purpose flour
1/3
cup unsweetened cocoa
1
teaspoon baking soda
1
cup sugar
1/2
teaspoon salt
5
tablespoons neutral oil (like corn, canola, or vegetable)
1
cup cold water
1 1/2
teaspoon vanilla
1
tablespoon cider or white vinegar
Confectioners' sugar (optional, for dusting)

Now that's a recipe that has been around for a while. Can you give us the proportions of flour, sugar, cocoa, and other leavening?