Chocolate layer cake with raspberry filling and chocolate ganache
Ganache-ing their terrible teeth
I love birthdays. They are an excellent excuse to make extravagant cakes, which I love to do and would probably do more often if people didn’t seem to find it extremely strange when the occasion for said cake is, for example, a Thursday. This week had two birthdays, a coworker’s and a friend’s, so it was practically required to craft something incredible. And so I made a cake without frosting.
Now, before you eye me skeptically and tell me that massive amounts of frosting are kind of the definition of incredible, let me tell you what I did instead: ganache. I’d heard of this food of the gods, of course, but I’d never made it and did not have a full appreciation for its true glory. You start with cream and a little sugar, then melt in a ton of chocolate, then (in this case) add some butter. Because it wasn’t rich enough to begin with. With this rock star cast of ingredients, I knew it would be good—I just didn’t know how good.
Can you tell that I liked it a little bit?
To understand what’s going on in this heavenly food, it helps to start with its main ingredients: chocolate and cream. Chocolate has a cocoa butter (the fat pressed from cacao beans) base with suspended cocoa particles, sugar crystals, and milk proteins in proportions that change with the type (dark vs. milk) and quality of the bar. Cream is essentially butterfat suspended in water—heavy whipping cream in the US has 38% fat. When chocolate melts in cream, cocoa butter softens and releases the cocoa particles and sugar to do as they like, the sugar obeys its basic chemical inclinations and chooses water over fat. The chocolate’s sugar dissolves in the water portion of the cream and forms the base for a new suspension. The solid cocoa particles, as well as the fat particles from both original ingredients (the butterfat and cocoa butter), can’t dissolve in this water-based solution so they stay suspended throughout it.
Two factors determine the properties of a ganache: the ratio of chocolate to cream and the process of cooling that it undergoes. Equal parts of cream and chocolate means that there is a comparatively large proportion of the sugar-water solution that forms the base of the ganache, so it is soft. A firmer ganache has more chocolate, meaning that it has more suspended particles (the cocoa solids and cocoa butter) for the same amount of liquid. In this case, there is such thing as too much of a good thing: if the proportion of chocolate is high, the fat droplets can reach a critical mass and separate from the water-based part of the ganache. Not exactly the goal.
The cooling process also plays a role in how the ganache turns out. If it cools fast (you put it in the fridge right after making it), it solidifies in random patterns and will melt at a lower temperature when re-warmed. If, on the other hand, the suspension cools slowly at room temperature, many more crystals form—it is more ordered. This allows it to soften and melt more slowly.
But don’t worry about the possibility of something going wrong. The chemistry may be a little involved, but at its heart, ganache is just amazing ingredients becoming even more amazing together.
Chocolate cake with raspberry filling and chocolate ganache
3 oz. semisweet chocolate
1 ½ c. hot brewed coffee (I must confess, I used instant. It was fine)
3 c. sugar
2 ½ c. flour
1 ½ c. unsweetened cocoa powder
2 t. baking soda
¾ t. baking powder
1 ¼ t. salt
¾ c. vegetable oil
1 ½ c. buttermilk (or regular milk curdled with 1 ½ T. lemon juice, see Cornbread casserole)
¾ t. vanilla
Melt the chocolate into the coffee and stir until the mixture is smooth, then let cool. Mix the sugar, flour, cocoa powder, baking soda, baking powder, and salt. In another bowl, beat the eggs with an electric mixer until they are thickened (about 5 minutes if you are still dreaming about the KitchenAid stand mixer that will one day grace your apartment and are using a handheld, or 3 if you have already achieved that dream). Add oil, buttermilk, vanilla, and chocolate/coffee mixture to the eggs, and combine well. Finish off the batter with the sugar mixture, mixing just until it is well mixed.
Divide batter into two oiled and floured cake pans (my greasing was insufficient and I regretted it later) and bake at 300 degrees F for an hour to an hour and 10 minutes. Mine took a little longer because they were about to overflow their pans—check for doneness with a toothpick or a fork in the center. Let cool completely before frosting.
10-oz. bag frozen raspberries, thawed
¼ c. sugar
1 T. cornstarch (I substituted 2 T. flour and it worked fine)
Puree the berries with an immersion blender or food processor. Add the sugar and thickener and cook on the stove until it boils down to the consistency you want.
And finally, the ganache:
½ lb. semisweet chocolate, finely chopped
½ c. heavy cream
1 T. sugar
1 T. light corn syrup
1/8 c. (¼ stick) butter
Heat the cream, sugar, and corn syrup to boiling over medium-low heat and stir until sugar dissolves completely. Remove pan from heat and add chocolate, stirring until it is melted. Cut the butter into cubes and add to ganache to enhance deliciousness, stir until smooth. Cool slowly—preferably at room temperature, but over ice water also works well.
I cut each of my cake layers in half to have more surface area to cover with yummy raspberries (not my idea, thank Smitten Kitchen) and frosted the outside with the ganache. Top with sprinkles (all recipes should end with this sentence).
This recipe, like most of my recipes lately, comes from the awesomeness that is Smitten Kitchen.