This is the most incredible, luxurious, intensely chocolate dessert! It is a great celebration cake and I have made it for anniversaries and graduations. Last time was to celebrate Grant’s high school graduation. It is a shame that I rarely make it because it really is amazing and special. I had not made it in about ten years, and when I looked for the recipe, I could not find it online, but, thankfully, I found the old paper copy in my pantry. The recipe is from Ghirardelli and I found it in a Chocolatier magazine and copied the page many years ago. Naturally, their recipe calls for Ghirardelli chocolate, which is fabulous, but I use the Pound Plus chocolate from Trader Joe’s, which is perfectly delicious and much less expensive.
There are several components and steps, but don’t let that stop you from making this. It needs to be made ahead and can be done over a few days’ time. All in all, it doesn’t take that much time for each step. I make the cake one day and the next day make the mousse and soaking syrup and assemble it, then I freeze it for several days, until the day I want to serve it. On serving day, just glaze the frozen cake and refrigerate for at least a couple hours before serving.
It is on my to-do list to make a gluten-free version and I will make two, one with this cake recipe but substituting a gluten-free 1:1 flour blend, and for comparison, a second using another gluten-free chocolate cake recipe that I know is successful, and then follow the rest of the elements and instructions. I will update with the winner.
CHOCOLATE ESPRESSO CAKE:
- 6 ounces bittersweet chocolate, coarsely chopped
- 1 cup cake flour, sifted
- 3/4 teaspoon baking soda
- 1/8 teaspoon salt
- 5 tablespoon butter, softened to about 65°F
- 1/2 cup plus 2 tablespoons granulated sugar, divided use
- 2 large eggs, separated, room temperature
- 1/3 cup sour cream, room temperature
- 1/2 cup brewed coffee, cooled
- 1/8 teaspoon cream of tartar
ESPRESSO SOAKING SYRUP:
- 1/4 cup water
- 3 tablespoons granulated sugar
- 2 teaspoons instant espresso powder dissolved in 2 teaspoons hot water
CHOCOLATE ESPRESSO MOUSSE:
- 5/8 cup (10 tablespoons) whole milk
- 2 tablespoons freshly ground coffee beans
- 9 ounces bittersweet chocolate, coarsely chopped
- 2 teaspoons vanilla extract
- 1 1/2 cups heavy cream
CHOCOLATE GLAZE:
- 8 ounces bittersweet chocolate; chips or finely chopped block chocolate
- 1 cup heavy cream
- 2 tablespoons light corn syrup
- 1 teaspoon vanilla extract
To make the cake:
Preheat oven to 350°F with rack in the center. Thoroughly grease a 9-inch round cake pan and line it with a circle of parchment paper, then dust with flour or sugar and remove any excess by tapping the pan upside down.
Gently melt chocolate, either in a double boiler on low or carefully in the microwave on half power while stirring every 30 seconds. Set aside and allow it to cool while preparing the cake.
Whisk together flour, baking soda, and salt in a medium mixing bowl and then sift it.
Using an electric mixer with the paddle attachment, beat butter until creamy, 1-2 minutes. On medium speed, gradually add 1/2 cup sugar and then beat at high speed until light and creamy, 2-4 minutes. Mix in vanilla extract and then add egg yolks one at a time, scraping down the sides of the bowl after each one and as necessary. Add sour cream and mix and then add melted chocolate and mix until well blended. On low speed, and in three additions, add flour mixture, alternating with the coffee in two additions. (Mix in 1/3 flour, then mix in 1/4 cup of coffee, then mix 1/3 of the flour, then the rest of the coffee, and end with the last of the flour mixture.) Mix just until blended.
In a clean, dry bowl, use the whisk attachment of an electric mixer to beat egg whites and cream of tartar until frothy. Start on medium speed and once the egg whites are frothy, increase the speed to medium-high and beat until soft peaks begin to form. Gradually add in the remaining 2 tablespoons sugar and then beat at high speed until stiff, glossy peaks form.
Use a rubber spatula to gently fold beaten egg whites into the chocolate batter until there are no white streaks. Scrape batter into the prepared 9-inch round cake pan and smooth the top. Bake for 30-35 minutes until a toothpick inserted in the center comes out clean. The edges should slightly pull away from the sides of the pan. Remove from oven and cool on a wire rack for ten minutes. Then invert cake onto a cooling rack and remove the parchment paper. Allow to cool completely.
Make the soaking syrup:
Combine water and sugar in a small saucepan and cook over medium heat, stirring constantly, until sugar dissolves completely. Then bring syrup to a boil over high heat. Remove from heat and stir in dissolved espresso. Allow to cool.
To make the mousse:
Combine milk and ground coffee in a small saucepan and heat on medium-high until scalded; it will form little bubbles around the edges and steam will be rising, about 180°F. Remove from heat and allow to steep for 15 minutes. Then strain milk through a fine-mesh sieve (lined with cheesecloth is best). Return milk to saucepan.
Place 9 ounces of chopped chocolate in the bowl of a food processor and process until finely ground, about 20 seconds. (This can be done while the milk and coffee are steeping.) Heat the milk back to scalding and then pour the hot milk through the feed tube of the food processor while it is running. Continue to process until the chocolate is completely melted and smooth. Add vanilla and process briefly to blend. Scrape chocolate mixture into a large bowl.
In the bowl of an electric mixer, use the whisk attachment to beat cream until medium-firm peaks form. Gently fold 1/3 of whipped cream into chocolate mixture at a time. The first addition of whipped cream will lighten the mixture, making the next two additions easier. Refrigerate mousse until time for cake assembly, covering container if not assembling the cake in the next hour.
Assemble the cake:
Slice cake in half horizontally, making two equal layers. Put one layer in the bottom of a 9-inch springform pan. Brush layer with half of the espresso soaking syrup. Top with half of the mousse and smooth it out in an even layer, allowing it to fill the gap between the cake and side of pan. Put second cake layer on top of mousse and brush with remaining espresso syrup. Top with remaining mousse, again spreading it even and smooth. Cover with plastic wrap and freeze until firm, at least three hours or up to a week.
* If preferred, line the pan with plastic wrap: take two long sheets of plastic wrap and lay one strip of plastic wrap on the counter and then lay the other strip crossways. Place the bottom of the springform pan on top of the center. Fold the plastic wrap on top of the pan bottom and take the side of the springform pan and close it as you normally would, but with the plastic inside the side part. The plastic will be underneath the bottom part, but inside the pan. Then arrange the plastic wrap as smoothly as possible inside, folding it over the top of the sides so that it is out of the way while assembling the cake. Proceed with assembly instructions as above.
To make glaze:
Place chocolate in a medium heat-proof bowl and set aside while heating cream. Using a small saucepan over medium heat, bring cream and corn syrup just to a simmer. Remove from heat and pour hot cream over chocolate. After allowing it stand for 30 seconds, gently stir or whisk (without adding air) until chocolate is melted and glaze is smooth. Stir in vanilla extract.
Finish cake with glaze:
Remove cake from freezer and uncover it. If plastic wrap was used for the sides, carefully remove it. Otherwise, dip a long, thin-bladed knife in hot water and wipe dry. Run hot knife between side of pan and cake to separate cake from pan. Continue this process, reheating knife in hot water and wiping dry as much as necessary. Once it is separated, remove springform pan sides. Set cake on a wire rack set over wax paper or a clean baking sheet. Pour glaze all over top of cake and let it drip down the sides. Use an offset or straight icing spatula to smooth glaze and cover cake completely. Transfer cake to a serving platter or plate. Scrape leftover glaze into a small sealable plastic bag or small piping bag. Cut a small hole in corner of bag and drizzle glaze in a diagonal pattern over top. Garnish with chocolate espresso beans or chocolate shavings. Refrigerate cake for at least two hours before serving.
Serves 16. Store in refrigerator up to four days.