Put that box mix away! You don't need THAT anymore, you have crazy cake now—frequently known in my parts as "THE Chocolate Cake." As in, "Anne, bring THE chocolate cake to dinner, please."
The history of this cake goes back approximately 100 years, and has almost as many names as it has versions—Crazy Cake, Raisin Cake, War Cake, Depression Cake, and Wacky Cake. Most people cite its origins around WWI, during the time of rationing, when sugar was at an ultra premium and boiled raisins were frequently substituted as sweetener. This particular version of this recipe was more typical during the Great Depression, when sugar was handy, but eggs, milk, and butter were costly.
I gotta hand it to our great grandparents' generation, they sure did master the art of substitution.
What makes this cake so amazing these days is that in the age of food allergies and special diets, this cake's long history makes it naturally free of 7 out of 8 of the most common food allergens. Having no eggs, butter, or milk also makes it vegan! Because you're not dealing with a risk of salmonella, and there's no electric mixer, this recipe is friendly for kids to make, and everyone can lick the raw batter. Yup, lick it right out of the bowl, guilt free. It's traditionally mixed with a fork in its own baking pan and served right out of there, too—making it minimal equipment and easy clean-up.
The fact that it's moist, semi-sweet, dense (almost like a delicious brownie), made with ingredients you probably already have in your pantry, and that people would never guess that you're feeding them a vegan cake, is just icing on the . . . cake.
For the one-pan recipe method:
Put all of the dry ingredients in your 9 x 13 pan, and sift them together well with a fork.
Make three wells of increasing size for the vanilla, vinegar, and oil. Pour the water over the top of everything, and stir very well with a fork or spatula, making sure to take extra care to mix the corners and edges.
Bake at 350F, for 30-40 minutes, until toothpick comes out clean.
If you would like a traditional layer cake or cupcakes:
Follow the same instructions above in a mixing bowl
Either grease/flour your pan (if you need to stay vegan, stick to a vegan shortening for this), or pour into cupcake tins lined with a paper liner (~20-24 cupcakes) for ease of serving, and reduce baking time (same temperature, ~20-25 minutes).
Remember the grade school volcano project with the vinegar and baking soda? The carbon dioxide released by mixing the two will be what helps the cake rise, so don't let the batter sit for very long before baking (don't worry, you won't taste the vinegar at all). For this same reason, you must also mix the batter by hand instead of using an electric mixer.
Cool your cake or cupcakes before attempting to frost. Top your cake simply with icing sugar, or you can use a vegan chocolate frosting recipe.