Chocolate Oatmeal Stout Cake ft. Pumpkin Ale Frosting + Dark Chocolate Malt Ganache
Starbucks had its moment in the spotlight, but now it's time for another fall-drink-based cake - may I introduce to you, the Stumpkin (the drink), courtesy of Heartland Brewery in New York City. Equal parts Farmer John's Oatmeal Stout and Smiling Pumpkin Ale, this mixed beer concoction combines the hearty roasted chocolate flavor of the stout with the sweet spicy body of the pumpkin ale (do I sound like a beer connoisseur yet?)
I'm a fan of the version that comes in a pint glass, so that can only mean one thing - if you can drink it, you can bake it. Thanks to some home-brewing friends, several Sam Adams brewery tours over the years, and the Internet, I am somewhat aware of how beer is made. The overly-simplified process (and don't hold me to it) goes something like: barley grains are steeped (soaked in water) and kilned (dried in an oven) to become malt (fermentable sugars), the malt mash solution is boiled with hops for seasoning (bitterness to balance the sweeter malt flavors) and yeast is added to begin fermentation, which releases carbon dioxide and ethyl alcohol during several weeks of conditioning. Then, beer.
Of course the real process is more complex than that, but just knowing those steps gave me enough material to translate into a cake. I recommend starting with a dark chocolate cake mix (though chocolate is fine too), and you'll need an oatmeal stout and a pumpkin ale as well (feel free to drink the remainder throughout the brewing, er, baking process). The Stumpkin cake is rich without being too sweet, due to the dark chocolate in the ganache and the smooth dark beers in the cake and frosting.
The key ingredient (in my opinion) - which is optional (depending on if you can/wish to purchase malt from a homebrew store or the Internet) - is the ground malt powder made from roasted barley grain. I bought a pound of this chocolate rye malt, soaked it in water, roasted it in the toaster oven, and then ground it into a fine powder with a blender (or food processor).
This mimics the process of malting in the actual brewing process at a much smaller scale - the point is to release the smoky roasted flavors of the grains. The picture below shows that the 'powder' looks a bit more like dirt than a fine sugar, but it really adds an earthiness to the stout cake and grittiness to the dark chocolate ganache. The malt is completely optional but if you choose to make it, I would add 1 tablespoon into the cake mix and then 1-2 tablespoons into the ganache recipe.
chocolate oatmeal stout cake
1 box dark chocolate cake mix
1-1/4 c. oatmeal stout
2 tbsp pumpkin puree
1 tbsp roasted malt powder (see below)
1/4 c. vegetable oil
Preheat oven to 350 degrees F, grease pan with butter or a non-stick spray like PAM. In a large mixing bowl, beat eggs, oil, oatmeal stout, and pumpkin puree until smooth. Slowly add in cake mix and malt powder, beating well after each addition. Pour batter into greased 8” round pans and bake according to times on the back of the box.
pumpkin ale frosting
1/4 c. shortening
4 c. confectioners sugar
3 tbsp. heavy cream
1 tbsp pumpkin puree
2 tbsp pumpkin beer or ale
1 tbsp cinnamon
1 tsp pumpkin spice
orange food coloring (optional)
Beat shortening, cream, pumpkin puree, pumpkin ale, cinnamon, and pumpkin spice on low speed until smooth. Slowly add in sugar and beat on high speed until frosting forms. Add gel food coloring for orange frosting.
dark chocolate malt ganache
10 oz. dark chocolate / semi-sweet chocolate chips, chopped
1 cup heavy cream
1-2 tbsp. roasted malt powder (see below)
In a small saucepan on the stovetop, bring cream and malt powder (see below) to a boil. Remove from heat, added in chopped chocolate, and whisk mixture until blended. Let cool and thicken without hardening. Spread onto frosted cake, letting colors blend together.
roasted malt powder
1 c. chocolate barley malt
Soak barley grains in a bowl of water for 1 hour. Spray baking sheet with nonstick spray and spread wet grains in a thin layer onto the sheet. Roast in oven or toaster oven for 1 hour at 400 degrees F, stirring every once in awhile so grains do not start to burn (your oven may also become smoky as the water releases). Let grains cool and then use a blender or food processor to grind the grains into a fine powder.