Sourdough Chocolate Cake

Why no, it's not supposed to be half frosting. Why do you ask?

As the relatively unappealing image above may demonstrate, this recipe is certainly not one of my resounding successes. That said, it wasn't an appalling failure either; consider it something of a happy medium--a bold recipe that is bravely willing to straddle the line between "meh" and "pants-wettingly-awesome".

Comparing my image above with that displayed on the main recipe's page (source) raises a couple of questions:

1) What went wrong?

... Upon reflection, that's the only question I have. And truth be told, I think I have an answer; unfortunately, there's rather little I can do about it. But far be it from me to deny my readers the experience of reading my prose simply because I couldn't handle a few simple steps. Onward!

Sourdough Chocolate Cake
(Approrpiated from King Arthur Flour's blog)

Ingredients
Cake
1c Active sourdough starter
1c Milk
2c Flour
1.5c Sugar
1c Vegetable oil
2tsp Vanilla
1tsp Salt
1.5tsp Baking soda
3/4c Cocoa powder (not Dutch process)
2 Eggs

Icing*
6c Powdered sugar
1/2c Butter, softened (1 stick)
1/2c Plain yogurt
1/2c Peanut butter
1tbsp Hot water

Garnish
1/3c Chocolate chips
1tbsp Milk
1tbsp Corn syrup

* You'll notice that I changed the type of icing used from coffee (original) to peanut butter (mine). This is not entirely due to flavor preferences; I also couldn't find any espresso powder at the store, so came up with an alternative on the fly.

Preheat oven to 350F

Procedure
In order to prepare properly, I activated my starter the previous evening (in accordance with standard sourdough preparation: remove from fridge, add 1/2c warm water and 1c flour, let sit for a while) and then added the milk and flour the following morning. I then proceeded to let it sit on the counter until I was ready to deal with it. Contrary to the main page's instructions, mine didn't appear to rise over the course of the day, but such things are really hard to measure anyway.

While the dough is resting/rising(ish), beat the sugar, oil, vanilla, salt, baking soda, and cocoa powder in a mixing bowl until well-blended. Add the eggs individually, allowing each to fully incorporate before adding the next.

Once the mixture is ... mixed, and the dough has risen (ish), add the chocolate mixture to the dough and stir to incorporate. This will require a great deal of patience, as a relatively thick dough doesn't like dissolving into a liquid (more on this later). Pour the mixture into a greased 9x13 pan and bake for about 40 minutes.

As the cake cools, you may prep the icing. Add the butter, peanut butter, water, and yogurt to a small saucepan and melt over medium heat, stirring frequently. (Note that if you stop stirring for too long, the peanut butter will probably scorch on the bottom of the pan.) After the mixture starts to boil, pour it over the powdered sugar and stir until thoroughly blended. Pour the resulting goo over the cooling cake.

The final garnish is optional, but helps add a bit of character to the cake's appearance. Simply melt the chocolate chips, corn syrup, and milk in a small bowl (the microwave works well for this, just go slowly) and then drizzle it over the top of the frosting.

Yeah, I'm horrible at the garnish part.

Lessons Learned
As I noted above, I encountered some trouble with the process of mixing the dough with the chocolate batter--notably, that they don't want to mix. They hate mixing. The sourdough has no trouble breaking up into smaller chunks and vanishing into a puddle of brown, but they're still there, waiting, like little chewy time bombs planning to wreak havoc on the texture of this cake. And that's precisely what happened to me: since you typically don't want to overmix gluteny goods, I erred on the side of caution and left some small fragments of dough scattered throughout my batter. These fragments, upon encountering the warm oven environment, transform into indigestible lumps of textural devastation in an otherwise mediocre cake. The best comparison I can come up with is akin to baked wafers (another disaster I've encountered first-hand, mind you): they're chewy and don't break down in the mouth, leaving you dissatisfied and curious as to what's going wrong.

The only other major problem I had was due entirely to my own modifications: as stated, I couldn't get espresso powder at the store, and settled on peanut butter as a substitution. However, I failed to take into consideration the fact that coffee (bitter) and a ton of sugar (sweet) mixes with yogurt (sour) to make something relatively balanced in the original recipe. My own version, peanut butter (sweet), sugar (sweet), and yogurt (sour), however, is extremely sweet (unsurprisingly), and completely overwhelms the cake itself. If I were to try the same substitution again, I would make a cream cheese based frosting rather than the powdered sugar type, as that would rebalance the flavors and allow the cake to shine through.

A final note: the cake's texture wasn't exactly cake-like (sourdough clumps aside); it was closer to a brownie. I suspect that in part this is because my sourdough yeast may not be active enough to provide the rise I need, but some further experimentation is needed to reach any real conclusion there. All in all, this was an interesting recipe, but not one I plan to attempt again; I'm content to make my cakes with chemical leaveners and leave the yeast to the goods they do best.