Saturday, April 14, 2012

Celebration Cake! Dark Chocolate Salted Caramel Layer Cake


I love any excuse to bake a delicious chocolatey cake and what better reason than to celebrate two birthdays!  We celebrated my brother and sister-in law's birthdays over Easter weekend so I decided to attempt a new cake.  I saw this cake a few months back on Pinterest and was waiting for the perfect time to give it a try.  It worked out great because I was able to make the cake layers Thursday night and assemble and frost the cake Friday morning before the family came to town.  It kept really well in the fridge until Saturday night when we finally got to dig in.  If you are like me, you probably only make celebration cakes at busy times, such as when your entire family is in town for a weekend, or you are traveling a distance to be at a special event.  Hence, I believe it's important to find recipes that can be made ahead of time to help maintain your sanity.  This decadent cake fits the bill!    

I warn you in advance, there are several difficult steps to this cake, but nothing you can't master with a little time (and a chemist for a husband!).  The cake is comprised of three layers of moist chocolate cake filled with silky, salted caramel Swiss meringue buttercream and enrobed in rich chocolate frosting.  This was my first attempt making Swiss meringue buttercream and while it was a bit tricky, the results are totally worth it.  I almost passed out on the kitchen floor after my first taste!    

Dark Chocolate Salted Caramel Layer Cake
from Annie's Eats and Sweetapolita (check out their blogs for beautiful pics of the finished cake!)

2¼ cups all-purpose flour
2¼ cups sugar
1 cup plus 2 tablespoons dark unsweetened cocoa powder
2¼ tsp. baking soda
1½ tsp. baking powder
1½ tsp. salt
6 tbsp. vegetable oil
1 cup plus 2 tbsp. buttermilk
1 cup plus 2 tbsp. brewed coffee (Note: This enhances the chocolate flavor.  Your cake will not taste like coffee.)
3 large eggs, at room temperature
1 tbsp. vanilla extract

Salted Caramel Filling:
1 cup sugar, divided
¼ cup water (I used closer to 1/3 cup after my first attempt failed)
¼ cup heavy cream
Generous pinch of sea salt, such as fleur de sel
4 large egg whites
1½ cup (3 sticks) unsalted butter, at room temperature

Chocolate Frosting:
12 oz. good quality semisweet or bittersweet chocolate, finely chopped
¼ cup unsweetened Dutch-process cocoa powder
¼ cup very hot water
1 cup plus 2 tbsp. (18 tbsp.) unsalted butter, at room temperature
1/3 cup plus 1 tbsp. confectioners’ sugar
Pinch of salt

Fleur de sel, for finishing

Preheat the oven to 350˚ F.  Grease and flour 3 8-inch baking pans.  Line the bottoms with parchment paper rounds.  In an electric mixer (you could probably mix by hand but the mixer makes it very easy), combine the flour, sugar, cocoa powder, baking soda, baking powder, and salt.  Mix on low speed to blend.  Add the vegetable oil, buttermilk, coffee, eggs, and vanilla and mix on low speed until well blended and completely incorporated.  Divide the batter evenly between the prepared pans.  If you have a kitchen scale, you can use it to make sure you have equal amounts of batter in each pan.  Bake 20-25 minutes, or until a toothpick inserted in the center comes out clean.  Mine might have been a tiny bit under baked since they sunk a bit while cooling, but they tasted great!  Let the cakes cool in the pans about 15 minutes, then invert onto a wire rack and allow to cool completely.  Remove the parchment paper.

Caramel Buttercream Filling:
Place ½ cup plus 2 tablespoons of the sugar in a medium saucepan.  Mix in the water.  (As stated in the ingredient list, I used closer to 1/3 cup of water because I ruined my first batch when all the water boiled out).  Bring the mixture to a boil over medium heat.  Stop stirring and let the caramel cook, gently swirling from time to time, until it is a deep amber color.  Watch carefully because it will go from a beautiful caramel to burned if left for too long.  Remove the mixture from the heat and slowly whisk in the cream (warning:  It will bubble up so be ready for that) and then the salt.  Set aside and let cool. 

Next, combine egg whites and the remaining ¼ cup plus 2 tablespoons sugar in a heatproof bowl set over a pot of simmering water.  Heat, whisking frequently, until the mixture reaches 160° F and the sugar has dissolved.  I also had to do this part twice since I accidentally scrambled the egg whites the first try.  My temp registered closer to 140, so I would just watch carefully and if you see the eggs starting to scramble take it off the heat asap!  Transfer the mixture to the bowl of a stand mixer fitted with the whisk attachment.  Beat on medium-high speed until stiff peaks form and the mixture has cooled to room temperature, about 8 minutes.  The bowl will feel cool to the touch.

Reduce the speed to medium and add the butter, 2 tablespoons at a time, adding more once each addition has been incorporated.  If the frosting looks soupy or curdled, continue to beat on medium-high speed until thick and smooth again, about 3-5 minutes more.  Blend in the cooled caramel (reheat caramel a minute or so if it has hardened too much) until smooth and completely incorporated, scraping down the sides of the bowl as needed.

Chocolate Frosting:
Place the chopped chocolate in a heatproof bowl set over a pan of simmering water.  Heat, stirring occasionally, until the chocolate is completely melted and smooth.  Set aside and let cool to room temperature.  In a small bowl, combine the cocoa powder and water and stir until smooth.  In the bowl of an electric mixer, combine the butter, confectioners’ sugar and salt.  Beat on medium-high speed until light and fluffy, about 5 minutes.  With the mixer on low speed, gradually blend in the melted and cooled chocolate until well incorporated.  Blend in the cocoa powder-water mixture until smooth.

To assemble the cake, level the cake layers if necessary.  Place one of the cake layers on a cake board or serving platter.  Top with half of the caramel buttercream and smooth in a thick, even layer.  Place a second cake layer on top and smooth the remaining caramel buttercream over that.  Place the final cake layer on top.  I put the top layer upside down to make the top nice and flat.  
Cover the top and sides of the cake with the chocolate frosting and smooth with an offset spatula.  Refrigerate until ready to serve.  Because of the high butter content in the frosting and filling (5 sticks!!), we found it was best at room temperature which took about two hours out of the fridge.  Before serving, sprinkle with fleur de sel.