Chocolate-Espresso Dacquoise

As soon as I saw this recipe on Cook's Illustrated I knew that I wanted to try it.  I got the occasion to do so during the holidays.  This was my main dessert on my sweets table when I was hosting Christmas Eve supper with the family.  It is a showstopper dessert with many layers of flavours that just married so well together.  

There is a disclaimer that this recipe is not for beginners but in a way that's one of the reasons why I loved it so much.  This recipe was so involved and required a lot of steps which had new techniques for me.  It was one of those recipes that challenged me and set the bar, quite high.  I had previously made a cake for my best friend last year with similar profile flavours, such as chocolate and hazelnut, and it was also layered in a similar way.  That also was a labour of love but the results were not as astonishing.  Unfortunately, the recipe had a genoise cake that turned out to be too dry.  However the silver lining of the story is that within the following days, the cake improved with time and became more moist.  It was a moment where I gained more experience and I felt more confident in tackling something of that nature again.  Although this time it was a real success!  

A dacquoise is a French cake that contains nut meringue (typically hazelnut and sometimes almond) and it is layered with buttercream.  There are a few components with this dacquoise that make it over the top.  The buttercream is a German buttercream, which happens to be a new baking technique for me.  It makes use of the remaining egg yolks (yay! no waste!) and is made from a pastry cream rather than hot sugar syrup.  Also, the German buttercream is flavoured with espresso and Amaretto!  Need I say more?  Oh, but there is more!  There's a dark chocolate ganache between each meringue layer and the entire cake has a lovely coating of ganache.  Yum!

If you intend on making this recipe I'd suggest to make it for a special occasion, perhaps for a crowd because it serves many people and another plus is that it can be made ahead of time.  Actually, most of the components can be made throughout the week and then the cake can be assembled and chilled for 1 to 3 days.  I recommend splitting up some tasks otherwise it may seem too daunting to accomplish.  I have some pictures below to illustrate how to do things step by step.

As I learned with my previous chocolate hazelnut cake experience, some cakes get more moist with time.  The same holds true with this cake.  Since this cake has a meringue base it initially has a little crunch after the first day of being made.  However, I happened to enjoy French macaron cookies (which are also made from nut meringue) with a little bit of chew and less crunch.  So I preferred this dacquoise 2 to 3 days after it was assembled.  

The almonds, hazelnuts, cornstarch, and salt were ground finely in a food processor and then combined with sugar.

Egg whites and cream of tartar were whipped on a stand mixer until stiff peaks form.

The meringue and nut mixture was spread into a 13 by 10 1/2-inch rectangle on a piece of parchment paper placed on the underside of a greased baking sheet.  The meringue required a long time to bake in a low temperature oven and it was then cooled in the oven for a long time.  It can then be wrapped and stored at room temperature for up to 2 days.

The pastry cream can be made in advance and chilled in the fridge.  It was warmed a bit in the microwave before adding the other ingredients to transform it into the German espresso buttercream.

Once the espresso buttercream is made it is best to make use of it at room temperature and it should not be placed in the fridge because it will lose its proper consistency.  The buttercream should be finalized just prior to assembling the cake.

The chocolate ganache should also be made just prior to assembling the cake.  It can be cooled for a few minutes to achieve the right consistency.

The meringue was trimmed with a serrated knife to form a 12 by 10-inch rectangle.  Precision here is key, use a ruler and a gentle hand when cutting the meringue.  

The meringue was carefully scored until it was cut through to make four 10 by 3-inch rectangles.  Mistakes do happen and there may be cracks during the cutting process; I used those as middle layers.

1/4 cup of ganache was evenly spread over the surface of each meringue and was used as a way to hold the cracked pieces together.  It was refrigerated for about 15 minutes.  The remaining rectangle was topped with 1/2 cup buttercream. (This was be the bottom layer of the dacquoise.)

I flipped over one of the ganache-coated meringues and placed it over the buttercream, making sure to level it properly.  Then 1/2 cup of buttercream was spread on the top and the layering process was repeated with the remaining meringue pieces.

I used the remaining buttercream to coat the sides and the top of the cake.  The cake was refrigerated until the buttercream was firm.

The remaining ganache was warmed until it was fluid but not hot.  The ganache was poured over the top of the cake and layered evenly with an offset spatula.  The ganache was spread also along the sides while the chocolate was still warm, then I garnished the top with hazelnuts and almonds along the sides of the cake.  The cake can be chilled for 1 to 3 days and should sit at room temperature for 30 minutes before slicing and serving.

Chocolate-Espresso Dacquoise

Serves 10 to 12

Ingredients

Meringue

3/4 cup blanched sliced almonds, toasted

1/2 cup hazelnuts, toasted and skinned

1 tablespoon cornstarch

1/8 teaspoon salt

1 cup (7 ounces) sugar

4 large egg whites, room temperature

1/4 teaspoon cream of tartar

Buttercream

3/4 cup whole milk

4 large egg yolks

1/3 cup (2 1/3 ounces) sugar

1 1/2 teaspoons cornstarch

1/4 teaspoon salt

2 tablespoons amaretto or water

1 1/2 tablespoons instant espresso powder

16 tablespoons unsalted butter, softened

Ganache

6 ounces dark chocolate, chopped fine

3/4 cup heavy cream

2 teaspoons corn syrup

12 whole hazelnuts, toasted and skinned

1 cup blanched sliced almonds, toasted

For the Meringue:

Adjust oven rack to middle position and heat oven to 250 degrees.  Using ruler and pencil, draw 13 by 10 1/2-inch rectangle on piece of parchment paper.  Grease baking sheet and place parchment on it, ink side down. (Can use an overturned rimmed baking sheet.)

Process almonds, hazelnuts, cornstarch, and salt in food processor until nuts are finely ground, 15 to 20 seconds.  Add 1/2 cup sugar and pulse to combine, 1 to 2 pulses.

Using stand mixer fitted with whisk, whip egg whites and cream of tartar on medium-low speed until foamy, about 1 minute.  Increase speed to medium-high and whip whites to soft, billowy mounds, about 1 minute.  With mixer running at medium-high speed, slowly add remaining 1/2 cup sugar and continue to whip until glossy, stiff peaks form, 2 to 3 minutes.  Fold nut mixture into egg whites in 2 batches.  With offset spatula, spread meringue evenly into 13 by 10 1/2-inch rectangle on parchment, using lines on parchment as guide.  Using spray bottle, evenly mist surface of meringue with water until glistening.  Bake for 1 1/2 hours.  Turn off oven and allow meringue to cool in oven for 1 1/2 hours.  (Do not open oven during baking and cooling.)  Remove from oven and let cool to room temperature, about 10 minutes.  (Cooled meringue can be kept at room temperature, tightly wrapped in plastic wrap, for up to 2 days.)

For the Buttercream:

Heat milk in small saucepan over medium heat until just simmering.  Meanwhile, whisk yolks, sugar, cornstarch, and salt in bowl until smooth.  Remove milk from heat and, whisking constantly, add half of milk to yolk mixture to temper.  Whisking constantly, return tempered yolk mixture to remaining milk in saucepan.  Return saucepan to medium heat and cook, whisking constantly, until mixture is bubbling and thickens to consistency of warm pudding, 3 to 5 minutes.  Transfer pastry cream to bowl.  Cover and refrigerate until set, at least 2 hours or up to 24 hours.  Before using, warm gently to room temperature in microwave at 50 percent power, stirring ever 10 seconds.

Stir together amaretto and espresso powder; set aside.  Using stand mixer fitted with paddle, beat butter at medium speed until smooth and light, 3 to 4 minutes.  Add pastry cream in 3 batches, beating for 30 seconds after each addition.  Add amaretto mixture and continue to beat until light and fluffy, about 5 minutes longer, scraping down bowl thoroughly halfway through mixing.

For the Ganche:

Place chocolate in heatproof bowl.  Bring cream and corn syrup to simmer in small saucepan over medium heat.  Pour cream mixture over chocolate and let stand for 1 minute.  Stir mixture until smooth. Set aside to cool until chocolate mounds slightly when dripped from spoon, about 5 minutes.

Carefully invert meringue and peel off parchment.  Reinvert meringue and place on cutting board.  Using serrated knife and gentle, repeated scoring motion, trim edges of meringue to form 12 by 10-inch rectangle.  Discard trimmings.  With long side of rectangle parallel to counter, use ruler to mark both long edges of meringue at 3-inch intervals.  Using serrated knife, score surface of meringue by drawing knife toward you from mark on top edge to corresponding mark on bottom edge.  Repeating scoring until meringue is fully cut through.  Repeat until you have four 10 by 3-inch rectangles.  (If any meringues break during cutting, use them as middle layers.)

Place 3 rectangles on wire rack set in rimmed baking sheet.  Using offset spatula, spread 1/4 cup ganache evenly over surface of each meringue.  Refrigerate until ganache is firm, about 15 minutes.  Set aside remaining ganache.

Using offset spatula, spread top of remaining rectangle with 1/2 cup buttercream; place on wire rack with ganache-coated meringues.  Invert 1 ganache-coated meringue, place on top of buttercream, and press gently to level.  Repeat, spreading meringue with 1/2 cup buttercream and topping with inverted ganache-coated meringue.  Spread top with buttercream.  Invert final ganache-coated strip on top of cake.  Use 1 hand to steady top of cake and spread half of remaining buttercream to lightly coat sides of cake, then use remaining buttercream to coat top of cake.  Smooth until cake resembles box.  Refrigerate until buttercream is firm, about 2 hours.  (Once buttercream is firm, assembled cake may be wrapped tightly in plastic and refrigerated for up to 2 days.)

Warm remaining ganache in heatproof bowl set over barely simmering water, stirring occasionally, until mixture is very fluid but not hot.  Keeping assembled cake on wire rack, pour ganache over top of cake.  Using offset spatula, spread ganache in thin, even layer over top of cake, letting excess flow down sides.  Spread ganache over sides in thin layer (top must be completely covered, but some small gaps on sides are OK).

Garnish top of cake with hazelnuts.  Holding bottom of cake with 1 hand, gently press almonds onto sides with other hand.  Chill on wire rack, uncovered, for at least 8 hours or up to 72 hours.  Transfer to platter.  Cut into slices with sharp knife that has been dipped in hot water and wiped dry before each slice.  Serve.

Source: slightly adapted from Cook's Illustrated