Cuban Opera Cake

Description[]

This cake can be made a day ahead of time and kept refrigerated. Just allow to stand at room temperature for an hour before serving.

Preheat oven to 325°F.
Butter two 9" diameter cake pans with 2" high sides; line bottoms with parchment paper rounds.
Dust pans with flour; tapping out any excess flour.
Melt chocolate in the top of a double boiler over simmering water, stirring until melted and smooth.
Remove the top part of the double boiler and allow the mixture to cool until it is lukewarm.
Whisk flour, baking soda, and salt together in a medium-sized bowl.
Using an electric mixer, beat the sugar, butter, and vanilla in large bowl.
Add the eggs one at a time, beating well after each addition and stopping occasionally to scrape down sides of bowl.
Gradually beat in the lukewarm melted chocolate.
Beat in the dry ingredients using one third of the ingredients at a time alternately with half the sour cream, beginning and ending with dry ingredients.
Gradually beat in the crème de cacao and coffee.
Divide batter evenly between the two pans and smooth out the tops.
Bake until a toothpick inserted into the center of each comes out clean (about 35 minutes).
Cool cakes in pans on racks 10 minutes.
Invert cakes onto 9-inch cardboard rounds or removable tart pan bottoms and allow them to cool completely on racks.

Melt milk chocolate in top of a double boiler over simmering water, stirring until smooth.
Set the top portion of the double boiler aside to the allow the chocolate to cool.
Whisk the sugar, egg yolks, 2 tablespoons of water, and the corn syrup in medium-sized metal bowl to blend.
Add ¼ cup of butter.
Set the bowl over the saucepan of simmering water and whisk constantly until the mixture reaches 170°F (about 4 minutes).
Remove the bowl and set aside.
Using an electric mixer, beat the mixture until it is completely cool and thick (about 6 minutes).
Gradually beat in ½ cup butter a bit at a time, mixing thoroughly before adding the next bit and stopping occasionally to scrape down sides of bowl.
Beat in the lukewarm melted chocolate.

Bring the cream, 2 tablespoons sugar and espresso powder to a simmer in a small saucepan on medium-high heat.
Whisk egg yolks and remaining 2 tablespoons sugar together in a medium bowl.
Gradually whisk in the hot cream mixture into yolk mixture.
Return the mixture to the saucepan and stir constantly over medium heat until thermometer registers 160°F (about 2 minutes).
Pour into a large bowl.
Add the softened gelatin, stirring until it is completely dissolved.
Using an electric mixer, beat the mixture until it is cool (about 10 minutes).
Using clean, dry beaters, beat cream and vanilla in medium bowl until stiff peaks form.
Fold the whipped cream into the coffee mixture.

Cut both cake layers horizontally in half.
Place 1 cake layer in bottom of 9-inch-diameter spring-form pan.
Cover with ¾ cup the buttercream.
Place a second cake layer on top of the buttercream layer and cover with mousse.
Top with a third cake layer.
Refrigerate 1 hour to allow the mousse to set.
Remove from the refrigerator and spread ¾ cup of buttercream over third cake layer.
Top with a fourth cake layer (don't worry, the cake now be taller than the sides of the pan).
Cover and refrigerate at least 4 hours, preferably overnight.

Stir sugar and 1 cup water in medium saucepan over medium heat until the sugar dissolves.
Increase the heat to high and bring to a boil.
Whisk in the cocoa then remove from heat.
Add the chocolate and whisk the mixture until it is smooth.
Let stand until cool but still pourable (about 2 hours).
Run knife around sides of the pan to loosen the cake, then release pan sides.
Scrape any excess mousse from sides of cake.
Transfer cake (still on the spring-form pan bottom) to a rack set over a baking sheet or other shallow pan.
Pour the glaze over the cake, allowing it to drip down edges onto baking sheet (use spatula to spread glaze over any uncovered spots).
Refrigerate at least 2 hours to allow glaze to set.