Chocolate Sourdough Cake for Guy Fawkes Day

Remember, remember the fifth of November --
The Gunpowder Treason and Plot.
I know of no reason the Gunpowder Treason
Should ever be forgot!

I'm not a big Guy Fawkes proponent (although I loved V for Vendetta), but the timing was right.  I bought this 3-D skull pan last year and had hoped to use it to make a sugar skull cake, but didn't get my act together soon enough, so it became a Guy Fawkes mask cake.

Some time ago, I made a "sourdough" starter from the wild yeast off my own organic grapes.  It's a very mild starter, not sour at all.  I don't bake bread often enough to use it all, so when I came across this sourdough cake recipe I was eager to try it out.  The recipe calls for King Arthur Flour's own sourdough starter, but by referring to the photos in their blog I was able to make adjustments so it would work with my own starter.

The planned baking day was very cool, and after 3 hours my flour/milk/starter mix hadn't budged.  After six hours it looked good, but by then it was late, so I put it in the refrigerator until the next evening and hoped for the best.  I forgot that wet flour, when left alone for a long period of time, will develop gluten all by itself.

Chocolate mixture.

Sourdough mixture, cocoa dusted.

When I went to use the mixture, it was as tough and stretchy as rubber!  Mixing it with the chocolate mixture was impossible, so I added a little milk to loosen things up.

In the end, I didn't get everything completely mixed together and there were small swirls of white in the final cake that baked up very tough.  I also made a mistake in not reducing the oven temperature to account for the longer baking time.  The pan comes with a recipe that calls for 65-75 minutes in a 325F oven. I had made note of the baking time, but not the temperature.  So I set the oven for 350F as called for in the KAF recipe and after 65 minutes it tested done.  Well, yeah.  Over done.  The best parts were the parts I cut off to get the two halves to fit together smoothly.  (It rose quite a lot in the middle, partially, I imagine, due to the overly hot oven.)  Next time I'll pay better attention... I hope.

Here's what I used:

1 cup "fed" sourdough starter
1 cup whole milk
2 cups all-purpose flour
1 1/2 cups granulated sugar
1 cup vegetable oil
2 teaspoons vanilla extract
1 teaspoon salt
1 1/2 teaspoons baking soda
3/4 cup unsweetened baking cocoa (not Dutch process)
1 teaspoon espresso powder
2 large eggs

Combine the "fed" starter, milk, and flour in a large mixing bowl. Cover and let rest at room temperature for 2 to 3 hours. It won't necessarily bubble, but it may have expanded a bit.

Preheat the oven to 350°F (325°F if using a 3-D pan). Lightly grease a 9" x 13" pan.  (If using a 3-D pan, lightly grease and then dust with flour or cocoa.)  In a separate bowl, beat together the sugar, oil, vanilla, salt, baking soda, cocoa. and espresso powder. The mixture might be grainy.  Add the eggs one at a time, beating well after each addition.  Gently combine the chocolate mixture with the starter-flour-milk mixture, stirring until smooth. Be sure to thoroughly incorporate the two.  This will be a gloppy process at first, but the batter will smooth out as you continue to beat gently.  Pour the batter into the prepared pan and rap a few time on the counter to release any large air bubbles.  (If using a decorative pan, this is especially important in order to settle the batter into the grooves.  For the skull pan, I poured in just enough batter to fill in the face and then rapped it hard several times to make sure the batter was fully filling the form.)  Bake the cake for 30 to 40 minutes, until it springs back when lightly pressed in the center, and a cake tester inserted into the center comes out clean.  Remove the cake from the oven; allow the 3-D pan to cool for 15 minutes before removing cake and cooling completely on a rack.

Constructing the cake was a little tricky, but went smoothly.  I sandwiched the halves with purchased dulce de leche, then went about constructing a nose out of cake scraps, also attached with dulce de leche.  (That stuff is sticky!)  I should note that both halves of the cake have a portion that rests on the plate, so your filling doesn't have to be firm enough to support the face.  (I hadn't been able to tell prior to making it.)  I also had to construct a lower lip.

 

I had yet another new thing to try in the frosting.  I find most frosting too sweet, so when I heard about cooked flour frosting that was less sweet, I had to try it.  You start with a loose roux, and that helps give body to the frosting.  I used half the full recipe and had just barely enough to cover the outside of the cake.

While very tasty, this frosting is not especially good for intricate decorating, as it has a whipped consistency that's difficult to smooth.  To get it truly smooth (and I did not do this), you should chill the completed cake to firm up the frosting, then use CLEAN fingers to smooth out the surface, just like cold butter.

Conclusion:  This cake was delicious!  Where I didn't over bake it, the cake was soft and moist.  It is not a very sweet cake, so your taste might require you to add another half cup of sugar or so, but with a sweet frosting it balanced out nicely as is.  I feel sure the issues with texture were due to over-developing the gluten in the flour and/or over baking.  I definitely will make this again, including adapting it to other flavors.

Recipe:  Sourdough Chocolate Cake via King Arthur Flour