Black Truffle-Pistachio Chocolate Cake

There’s no shortage of inspiration when it comes to using classic fall flavors in my baking. I love cinnamon spiced apples, anything pumpkin-filled and I’ve been dreaming of what to do with a fat butternut squash that’s been sitting on my kitchen counter for a good two weeks now. But after sampling some unique chocolates, I was inspired to make something a little less traditional this week.

Black truffles are most commonly used in savory dishes, but chocolatiers (such as the handsomely bearded Mast Brothers) have been incorporating them into chocolate. After sampling some, I was instantly smitten. Black truffles have a deep, earthy flavor that, to me, evokes feelings of the fall season. Depending on the variety, they’ve been described as “reminiscent of undergrowth, wet earth … or dried fruit with a hint of cocoa“. The trouble is, truffles are expensive, but luckily there are less expensive ways to incorporate them into your confectionery.

First of all, the cake is topped with Urbani’s black truffle bonbons (I bought mine here). They’re small, dense little candies filled with black truffle pieces, nuts and chocolate. They’re rich and earthy, and after tasting one I knew they were destined to adorn a chocolate cake filled with pistachio cream.

Secondly, the chocolate frosting is infused with a small amount of black truffle oil. Now, as far as I know, da Rosario is the only brand of truffle oil that is 100% organic and natural. Most other truffle oils contain no real truffles and instead are made with synthetic flavoring. That said, only a very small amount of truffle oil is used in the frosting, so purchase what your budget will allow. In general, real is always better than fake, but I view using the oil in the same way I view using artificial candy flavorings. It’s okay to use in small quantities, and when options are limited.

The pistachio filling is one of my favorite elements of this cake. It’s hugely rich with pistachio flavor, and that’s thanks to 11 ounces of pure pistachio paste. I couldn’t find it locally, so I ordered it online. You can find it here or in bulk here. It’s truly worth seeking out!

I really love the way this cake turned out. In fact, I told my husband I might enter it in the Tennessee State Fair next year. The black truffle flavors mixed with pistachio makes me think it’d be right at home at a fine Italian restaurant. Yesterday I had a slice with strong coffee, and let me tell you, I’m having trouble imagining anything better!

If you’re new to the flavor of black truffles, I suggest you familiarize yourself with it before embarking upon this cake. It’s an acquired taste for some people. Kitchen specialty shops often have oil tasting stations, which is a good way to explore their savory notes as the oils are usually served with garlicky seasonings and baguette rounds. To get an idea of how the flavor will taste in chocolate frosting, seek out a small chocolate bar or bonbons with black truffle shavings incorporated.

Black Truffle-Pistachio Chocolate Cake

Heather Baird

I recommend da Rasario 100% organic black truffle oil for the frosting. Truffle Hunter black truffle oil is also good and made with real black truffles, but be aware its flavor is also enhanced synthetically. Pungent oils must be used sparingly. If your truffle oil is mild, then the amount of oil added to the frosting can be increased to taste.

5 from 1 vote

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Prep Time 45 minutes mins

Cook Time 30 minutes mins

Total Time 1 hour hr 15 minutes mins

Course Dessert

Cuisine American

Servings 12

Ingredients

  

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Dark chocolate cake

• 8 ounces dark chocolate chopped
• 1/2 cup/113 g butter softened
• 2 cups/440 g light brown sugar firmly packed
• 3 eggs
• 1 teaspoon vanilla extract
• 2 cups/310 g all-purpose flour
• 1/4 cup/30 g dark cocoa powder
• 2 teaspoons baking soda
• 1/2 teaspoon sea salt
• 1/2 cup/121 g buttermilk
• 1 cup/235 ml piping hot water

Pistachio filling

• 1/4 cup/32g all-purpose flour
• 1 teaspoon fine grain sea salt
• 2 cups/460g buttermilk or whole milk
• 2 cups/1 pound unsalted butter softened
• 1 cup/200g granulated sugar
• 1 can 11 ounces pistachio nut paste

Black Truffle Chocolate Frosting

• 8 ounces semisweet chocolate chopped
• 1 1/2 cups heavy whipping cream
• 1/4 teaspoon black truffle oil add more to taste, but be careful – it’s strong stuff!
• 12 black truffle bonbons such as Urbani or black truffle chocolate squares (such as Mast Brothers)
• 4 ounces ground pistachios

Instructions

 

Dark chocolate cake

• Preheat oven to 350°F.
• Grease three 9-inch cake pans and line the bottoms with circles of parchment paper.
• Melt chocolate in a small saucepan over low heat, or melt in the microwave in a microwave-safe bowl at 30 second intervals. Set aside.
• Beat the butter with an electric mixer until creamy. Add sugar and beat until combined. Add eggs one at a time, beating each until just incorporated. Stir in melted chocolate and vanilla.
• Sift together the flour, cocoa powder, baking soda and sea salt; add to the butter mixture alternately with the buttermilk, beginning and ending with the flour mixture. With the mixer running, gradually add in the hot water. Mix until the batter in consistent (batter will be thin).
• Pour batter into prepared pans and bake for 30 minutes, or until a toothpick tester comes out clean. Cool in the pans on wire racks 10 minutes; remove cakes from the pans and cool completely on wire racks.

Pistachio filling

• In a medium saucepan, whisk together flour and 1/2 cup of the milk until smooth. Set over medium heat and let cook for 3 minutes, or until slightly hot. Whisk in remaining milk and salt. Whisk constantly until the mixture is thickened (almost like pudding). Remove from heat and pour into a separate bowl. Place in the refrigerator until completely chilled. When cool, mixture will be thick like set custard.
• In a large bowl (or bowl of a stand mixer, if you have one) beat the butter and sugar together until fluffy. Beat in chilled flour mixture one tablespoon at a time on medium-high speed. When all the flour mixture is added beat on high speed until light and fluffy, about 6 minutes. Rub a little frosting between your fingers, if sugar granules remain, beat for 4 more minutes, or until granules cannot be detected with fingers. Beat in the pistachio paste a little at a time until well incorporated.
• Place a chocolate cake layer on a cake stand or serving plate and top with three cups of pistachio filling. Top with another cake layer and spread the remaining 3 cups of filling over the second layer. Top with the third and final layer. Refrigerate the filled cake while you make the frosting.

Black Truffle Chocolate Frosting

• Combine the chocolate and whipping cream in a saucepan. Cook over medium heat, whisking occasionally. When the mixture is steaming and the chocolate is melted remove from the heat. Add the truffle oil (add more to taste, but be careful – it’s strong stuff!). Whisk the mixture until the chocolate is completely melted and incorporated into the cream. Pour into a shallow dish and chill until the mixture reaches a pudding-like consistency, about 1 hour.
• Beat the mixture with an electric mixer until it is thick and spreadable. Transfer 2/3 cup of frosting to a piping bag fitted with a large star tip. Frost the cake evenly with the remaining icing and pipe rosettes around the top edge of the cake. Top every other piped rosette with a black truffle bonbon. Sprinkle the top with ground pistachios. Place the cake on a large baking sheet and toss ground pistachios along the bottom edge of the cake, allowing the excess to fall back into the pan.
• Store the cake in the refrigerator. Serve chilled or let slices come to room temperature before serving – it’s good both ways!

Keyword black truffle chocolate frosting, dark chocolate cake, pistachio nut paste

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