Dark Chocolate Raspberry Truffle Cake

So here we have it.  A dark chocolate raspberry truffle cake.  The title is a mouthful in itself, and the cake is as well.  I promised you guys on Monday a much more over the top post this week, and this is it.  This beauty consists of three layers of intense dark chocolate cake, filled with both ganache and raspberry filling, and is finished off with lots of dark chocolate fudge frosting, real whipped cream, and fresh raspberries.  It's perhaps one of my favorite cakes that I've ever made...or eaten, for that matter!  

I've been wanting to make a big, fancy, bakery-style layer cake for some time now, but coming up with a flavor combination was giving me a really hard time.  Part of me wanted to go simple and classic, and maybe just make a really delicious yellow cake with chocolate frosting and rainbow sprinkles.  The other part of me wanted to go with a more unique approach, like Neapolitan, or chocolate and salted caramel.  I just couldn't decide! All I knew was that it had to somehow involve chocolate, because, well, you should know by now that chocolate and I share an inseparable bond.  Given this tiny requirement, I chose a sort of middle of the road option, and went with a classic flavor combination that I love, but one that isn't necessarily a classic flavor profile for cakes. Dark chocolate raspberry truffle cake- how could you not love this?!

This cake was absolutely perfect, in every single way possible, in my own opinion.  The chocolate cake was dark and intense, and was mildly sweet.  I actually had a very hard time not eating the cake that I cut off when I was leveling the cake layers, and I ultimately decided to give up, and allow myself to eat the cake bits as they were. They were delicious, and I just can't say no to plain cake!  I then decided to make a tiny cake "sandwich," and took two small pieces of the cake that had been cut off, and spread a little chocolate ganache and raspberry filling between them, to get a "preview"of what was to come.  I was so excited after having that tiny mouthful of cake with the fillings I had prepared, because I knew that if that little cake sandwich tasted that good, it was only going to taste even better with an outer layer of chocolate fudge frosting...and it did.  Oh man, did it taste good.

This cake, since it has a lot of components, is a bit more involved than the other recipes I've shared with you before.  It might be a lot of components, but fortunately, they're all actually very simple to prepare.  Begin by baking the cake, so that the cake layers have enough time to fully cool to room temperature (this is very, very, very important!).  As the cakes bake, you can go ahead and prepare the raspberry filling (you'll have some extra filling when you finish, and I highly recommend spooning the remaining raspberry filling over some scoops of vanilla ice cream), which takes all of about ten minutes or so, and then stick it in your fridge so that it gets nice and cold.  As the cakes cool, prepare the dark chocolate fudge frosting and the ganache for the filling (both of which you'll have some extra of as well, and I'm sure you can figure out some wonderful application for each), and set them aside to chill and firm up.  Then, all that's left is a little bit of cake assembly, some fancy (but not really) whipped cream piping action, and some decorative raspberry application, and that's pretty much it!  So really, the cake might seem a bit complicated off first glance, but when you really think about it, it's not that bad.  Just break everything down, handle everything one step at a time, and you'll be good to go!  I chose to use weighed measurements for the dry ingredients in the cake for some extra accuracy, and I think that is going to become a standard practice when I bake cakes- it's just a bit more reassuring to know that I'm using completely accurate measurements.  

This is a cake that will certainly impress anyone that tries it, and if you really want to impress people, I recommend making this cake the day before you plan to serve it.  I actually photographed and served this cake the day after I baked it, when it had had a chance to sit in my fridge overnight, and it made a huge difference, in my opinion.  As much as I loved that little preview cake sandwich that I described above, having a slice of the cake the next day was just so much better, because in that time, the chocolate cake had absorbed some of the raspberry filling and the ganache, so literally every bite of the cake was oozing with additional flavor.  The cake can be stored in the fridge on a cake stand until ready to serve, but once the cake is sliced, it needs to be stored in an air tight container in the fridge so that it does not dry out.  The cake will get better and better as time goes on; in fact, I just ate the last piece last night, a week after I made the cake, and the cake was as moist and fluffy (if not more) than the first day I tried it!  

Dark Chocolate Raspberry Truffle Cake
cake and frosting recipes from Sweetapolita; raspberry filling and ganache recipes from Annie's Eats

For the Dark Chocolate Cake

330 grams all purpose flour
600 grams granulated sugar
135 grams cocoa powder
1 tablespoon baking soda
1 1/2 teaspoons baking powder
1 1/2 teaspoons salt
3 large eggs, at room temperature
1 1/2 cups buttermilk, at room temperature
1 1/2 cups strong black coffee, hot
3/4 cup vegetable oil
1 1/2 teaspoons vanilla extract

For the Raspberry Filling

1 10-ounce bag frozen raspberries, thawed
1/3 cup sugar
3 tablespoons cornstarch
splash of fresh lemon juice

For the Chocolate Ganache

8 ounces semisweet chocolate, chopped
1 cup heavy cream
3 tablespoons butter

For the Dark Chocolate Fudge Frosting
6 tablespoons cocoa powder 
6 tablespoons boiling water
1 1/2 cups (3 sticks) unsalted butter, at room temperature
1/2 cup confectioner's sugar
pinch of salt
1 pound dark chocolate, melted and cooled 

whipped cream and raspberries, for decorating

Directions

Begin by preparing the chocolate cake.  Preheat the oven to 350 degrees F, and position a rack in the middle of the oven.  Prepare three 8-inch round cake pans by greasing them with nonstick spray, lining the bottoms with wax paper, spraying the wax paper, and then dusting the pans with flour.  

In the bowl of a standard electric mixer fitted with the paddle attachment, sift together the flour, sugar, cocoa powder, baking soda, baking powder, and salt. Stir together for 15 seconds to combine.  In a separate medium bowl, combine together the eggs, buttermilk, coffee, oil, and vanilla, and lightly mix together with a fork.  

Add the buttermilk mixture to the dry ingredients, and mix for two minutes on medium speed.  Make sure to occasionally stop the mixer to scrape the bottom of the mixer bowl, to ensure that all of the dry ingredients get incorporated (the batter will be thin).  Divide the cake batter evenly among the prepared pans.  

Bake the cakes for 20 minutes, and then rotate the pans in the oven.  Continue to bake the cakes until a toothpick, when inserted into the center of the cake comes out almost clean, about another 13 minutes.  Cool the cakes in the pans on a wire rack for about 20 minutes, and then invert the cakes onto the wire rack to cool completely.

While the cakes are baking, prepare the raspberry filling.  Drain the thawed raspberries, reserving the juice in a measuring cup.  Add enough water to the raspberry juice so that the total liquid comes to 1 1/4 cups.  Add this raspberry-water mixture to a medium saucepan, along with the sugar and cornstarch.  Heat over medium high heat, whisking every now and then, until the mixture begins to thicken (this can happen in a matter of a second, so keep your eye on it!).  Whisk so that no lumps form.  Once the mixture has thickened, remove it from the heat, and whisk in the lemon juice.  Stir in the drained raspberries.  Transfer the raspberry filling to a plastic container, cover, and chill until ready to use. 

Next, prepare the ganache.  Add the chopped semisweet chocolate to a heatproof bowl.  In a saucepan, heat the cream and bring it to a simmer.  Immediately remove the cream from the heat, and pour it over the chocolate. Allow the two to sit for a minute or two, and then whisk together to form a thick, smooth ganache. Whisk in one tablespoon of butter at a time, making sure each piece is incorporated before adding the next. Allow the ganache to sit for a little while so that it thickens.  If you are like me and find yourself pressed for time, you can speed up the thickening process by placing the bowl of ganache in the fridge and whisking it every ten minutes to ensure that it cools evenly.  This worked perfectly for me, and in about 30 minutes I had a nice, thick ganache. 

One last element left to prepare, the fudge frosting!  To prepare the frosting, begin by combining the cocoa powder and boiling water in a small bowl or measuring cup.  Stir until the cocoa powder has dissolved.  In a standard electric mixer fitted with the paddle attachment, beat together the butter, confectioner's sugar, and salt on medium high speed until the butter is light and fluffy, about 5 minutes.  Lower the mixer speed, and at in the cooled, melted chocolate, beating until it is well combined (scrape down the sides of the mixer bowl with a rubber spatula as needed).  Beat in the cocoa mixture until well mixed.  The frosting may be a bit on the thin side if your melted chocolate was too warm, but it will thicken as time passes.  The frosting can be prepared in advance and stored in the fridge; simply allow it to come to room temperature and beat on low speed before using it.  

Now that all the elements are ready, it's finally time to assemble the cake!  Begin by leveling your cake layers (make sure your cakes are COMPLETELY cool before doing this, otherwise you'll basically end up with a giant mess and have a really hard time- I know this from experience, so trust me on this).  An easy way for cutting perfectly level cakes is to place one of the cakes inside a quarter sheet pan.  Then, position a sharp serrated knife so that it is resting on the outer rims of the sheet pan (I have a really long serrated knife that is longer than the width of my quarter sheet pan, so I can rest the blade on the rims on both sides of the sheet pan).  Using a gentle back and forth sawing motion, work your way through the cake, making sure that the blade of your knife is constantly touching the ends of the sheet pan.  This way, you'll know that you're moving the knife in a perfectly straight, horizontal direction, and your cake layers will all be the exact same height and be perfectly flat.

Now it's time to fill the cake layers.  Fill a piping bag fitted with a plain, 1/2-inch round tip with about 1/2 cup of the ganache and set aside.  Place one of the leveled cake layers on a cake board or cake stand, and spread about 1/2 cup of the ganache in an even layer.  Pipe a border of ganache all the way around the top of the cake (this will act as a barrier to hold all the raspberry filling).  Spread about 1/3 cup of the raspberry filling over the ganache in an even layer.  Top this layer with a leveled cake, and add the ganache and raspberry filling in the same way as before.  Top with the remaining cake.  

To frost the cake, first apply a very thin coat of the fudge frosting all around the top and sides of the cake.  Use this first coat of frosting to even out the sides of the cake so that they're smooth. At this point, I refrigerated the entire cake for about a half hour to firm it up, as it was a little soft and hard to work with- my kitchen has a huge skylight that lets in a lot of sunlight, which also makes it very warm, so I usually refrigerate my cakes for a bit because of this.  Once the cake has firmed up, use the remaining frosting to apply a thicker coat of frosting all around the cake as desired.  Place the cake back in the fridge and let it chill until you're ready to serve it. Just before serving the cake, finish it off with some whipped cream rosettes and fresh raspberries, and enjoy!

Makes 1 3-layer, 8-inch cake