Easy Keto Opera Coffee Cake Recipe

Prepare the Keto Almond Joconde

1. Preheat the oven to 425 degrees F.  Line a rimmed baking sheet (I used 1n 18" x 13") with parchment paper.  Spray the parchment paper with cooking spray and set it to the side.
2. Place the egg whites and cream of tartar into a large, spotlessly clean bowl of your stand mixer and whisk on low, gradually moving to high speed, until the whites reach a  "soft" peak stage.
3. With the mixer on low speed, slowly sprinkle about half of the sweetener over the whites and then bring the speed back up to high until a stiff and glossy meringue forms and set the bowl to the side.
4. In a second bowl, add the eggs and sift in the remaining sweetener.   Whisk together the almond flour, whey and xanthan gum quickly in a small bowl before whisking it into the eggs.  Whisk on high (I used a handheld mixer) for 2 minutes or until the mixture becomes nice and thick.
5. Once incoporated, take ⅓rd of the egg white mixture and quickly stir it into the almond/egg bowl to loosen the mixture. (don't worry about deflated the egg whites at this stage).
6. Slowly fold in the loosened almond/egg mixture into the the egg whites, trying not to deflate the eggs until just combined.
7. Trickle in the melted butter and fold until incorporated.
8. Carefully spread the mixture onto the rimmed baking sheet and bake, 9-12 minutes, rotating the baking sheet halfway, until the sponge springs back when gently poked or it begins to brown.
9. Remove cake from the oven.  Place a second piece of parchment paper over a cooling rack.  Flip the cake onto the parchment paper and peel the top piece of parchment paper off of the cake.
10. Allow the sponge to cool.  Divide the cake evenly in 3 sections, measuring 6 inch sections.

* Once the sponge has cooled completely, feel free to wrap each section and place it in the freezer for up to a month

For the Sugar-Free Coffee Syrup:

1.   Combine the water, sweetness and instant coffee into a large glass measuring cup or a small microwaveable bowl.  Microwave on high for 1 minute and stir until the instant coffee and sweetener. 
2. Return to the microwave for an additional minute.  Add additional time until the water begins to boil and continue to allow to boil for 1 minute (mine took 2 minutes to boil and then 1 added additional minute, about 3 minutes).
3. Remove from the microwave and stir in the brandy, if using.  Allow the mixture to cool.

* The coffee syrup can be made ahead and cooled on the countertop covered or in the fridge overnight - allow the mixture to come to room temperature and stir before using.

For the Keto Coffee Buttercream

1. Combine the ¼ cup of the heavy cream with the instant coffee.  Microwave on high for 20-30 seconds or until the heavy cream begins to steam, but no boil.  Stir the instant coffee until fully dissolved.  Allow the mixture to cool completely.
2. Place the butter in a large mixing bowl and beat on high until the butter is light and fluffy.  Add in the sweetener and continue to beat until fully blended and the mixture is not grainy.
3. Add in the coffee mixture and remaining cold heavy cream.  Beat on high until thick and smooth.

* The buttercream can be kept in the fridge overnight - slowly bring it back to spreadable room temperature before using.  Also, feel free to add more sweetness to suit your taste.

Prepare the Chocolate Ganache and Glaze

1. Place the chopped sugar-free chocolate in a heatproof bowl.  Heat  170 ml of the heavy cream (you will have 50 ml leftover for thinning the ganache into the chocolate glaze) until steaming hot and pour it over the chocolate.  Leave the mixture for about 1 minute, then gently stir until melted and smooth.

* The chocolate ganache can be made ahead and refrigerated.  Bring the ganache back to spreadable room temperature before using.

Assemble the Keto Opera Coffee Cake

1. Take the coffee syrup and brush it over all 3 sections of the cake, on one side only.  You may need to do this several times, allowing time for the syrup to soak in.  Do not worry if you have some coffee syrup leftover.  Wait 10 minute for the cake to absorb the coffee syrup.
2. Place one layer of cake of the cake on a serving dish, syrup side up.  Evenly spread ½ of the buttercream frosting over the top of the coffee-soaked cake.  
3. Top with second layer of cake, coffee-soaked side up.  Spread ⅔ rds of the chocolate ganache over the coffee-soaked cake.  If chocolate ganache seems to soft, place the cake in the fridge to allow the ganache to harden slightly before assembling remaining cake layer.
4. Once ganache is firm, place the 3rd layer of cake, coffee-soaked side up, on top of the chocolate ganache.  Spread remaining ½ of the coffee butter cream over the top.  Place the cake back in the fridge for 30 minutes to harden the top layer of buttercream.
5. While buttercream is hardening, prepare the chocolate glaze but stirring in the remaining 30 ml of heavy cream.  If chocolate is too firm to mix, place it in the microwave on high for 15 second intervals until the heavy cream can be easily stirred into the chocolate.  The mixture should be pourable.  If the mixture still seems too thick, simply add 1-2 additional tablespoons of heavy cream until the mixture is pourable.
6. Once heavy cream has hardened, remove the cake from the fridge and carefully pour the lukewarm chocolate glaze over the top of the buttercream, allowing the glaze to drizzle down the sides.  Place the entire cake in the fridge to firm, about 30 minutes.
7. Once glaze has firmed, carefully trim the edges of the cake to cream a smooth border, showing different layers.  Use a sharp knife and cut the cake lengthwise down the center.  Then, cut each half into 4 even sections.
8. Serve at room temperature.