To better synchronize the downtime in these recipes, start making the salted caramel sugar first, then the Almond cake layer, while that is cooling down, start making the chocolate sponge cake layers.

Almond Cake Layer
 

• Preheat the oven to 175C°( 350F°) 30 minutes before baking.
   
• Line and lightly grease the sides and the bottom of a quarter sheet pan 22, 5 cm x 32,5 cm ( 9×13-inch) and line with parchment paper.  
   
• Grind the whole almonds with skins; If using a grinder as I do; Grind 200 gram whole almonds with skins, to make finely ground, Add the finely ground almond flour in a small bowl, add 25-gram Corn starch and 1 teaspoon baking powder, combine and set aside for now.
   
• If using a food processor; place 200 gram whole almonds with skin on, 25-gram corn starch, and 1 teaspoon baking powder in a food processor. Grind the almonds in a food processor, until the almonds are finely ground. About 30 seconds. Refrain from running the food processor continuously, as over-processing these almonds will release the nuts oils. Set aside for now.
   
• For the meringue mixture; Wipe the inside of a mixer bowl and whisk attachment with a paper towel dampened with a little lemon juice to eliminate any trace of grease. I know it adds a little time to the process. Still, it´s worth every extra second, as this step is so crucial to make sure your egg whites whip up well.
   
• In a stand mixer fitted with the whisk attachment, combine 140-gram egg whites, 1 pinch of salt, a pinch of cream of tartar ( if using), and beat on medium-high speed until stiff peaks form. About 3 to 4 minutes.
   
• Turn the mixer to medium-low, Slowly sprinkle in the sugar a tablespoon at a time; This step takes about 2 minutes.
   
• As soon as all of the sugar is added, turn the speed to high speed and whip until very stiff, glossy peaks form, about 5 to 7 minutes.
   
• Remove the bowl from the mixer using the whisk attachment or a silicone spatula, gently fold in the finely ground almonds and gently fold until incorporated.
   
• Scoop the almond meringue mixture into the prepared sheet pan, use your spatula to spread evenly, and eliminate any air bubbles.
   
• Bake-off immediately on the middle rack of the oven for 23 to 25 minutes. Mine was done at 23 minutes.
   
• Let the almond cake cool in the springform on a wire rack until cool. Wrap and freeze the cake layer in plastic wrap and freeze for 15 minutes before using or refrigerate for 30 minutes. The cake layer is less fragile when cold.
   
• Carefully with two hands turn the cake layer and peel off the parchment paper, place the almond cake layer on a flat cookie sheet ( that fits in your fridge) with a baking mat or parchment paper underneath. Set aside while you make the chocolate sponge cake layers.
   
• You can bake this almond cake layer up to a month in advance, After the cake layer is completely cooled to room temperature, wrap the cake layer with 2 layers of plastic wrap, followed by tin foil. Before using the cake layer, Remove the cake layer from the freezer about an hour before you plan to fill the cake.

Chocolate Sponge Cake
 

• Preheat the oven to 175C°( 350F°) 30 minutes before baking.
   
• Line the bottoms of two quarter sheet pan 22, 5 cm x 32,5 cm ( 9×13-inch) but leave the sides of the pans untouched. the cakes need to cling to the ungreased sheet pans to rise properly.
   
• In a medium-size bowl, whisk together the 110-gram all-purpose flour, 80-gram unsweetened cocoa powder, a pinch of salt, 1 1/2 teaspoon instant espresso powder, and 1 3/4 teaspoon baking powder, and then sift back into the bowl. Set aside for now.
   
• Make sure your eggs are at room temperate ( about 70F°/20C°). When you are ready to mix your cake, warm them ( in the shell) by placing them in a bowl of hot tap water for about 5 minutes before whipping up the eggs. Change the water if it cools don't too much.
   
•  Using a stand mixer fitted with the whisk attachment or a handled electric mixer, whisk the 8 large eggs ( 400 grams) and 1 teaspoon vanilla bean paste for 5 full minutes on high speed. Set a timer if you need to!
   
• Once the eggs are light in color and thick, slowly a tablespoon at a time, add the 250 grams of sugar and let it whip for 5 to 8 minutes more.
   
• Properly whipped eggs will lighten in color considerably and have the appearance of yellow cake batter. So when making this cake, it´s really important to get it thick and fluffy!
   
• Remove the bowl from the mixture, Sift in one-third of the flour-cocoa mixture, lightly combine with a balloon whisk or your whisk attachment until well incorporated. Repeat twice. Scrape down the side and the bottom of the bowl several times.
   
• Divide the chocolate batter into the two prepared baking sheets smooth the top evenly and gently run a spatula through the batter to pop any large air bubbles. Make sure you push the cake batter all the way to the edges. 
   
• Bake the first layer in the center of the oven for 13 to 15 minutes. -The time will depend on your oven, but it is around 13 to 15 minutes. This cake bakes very fast, keep an eye on the cake. Don't overbake it. Mine was done at 13 minutes.
   
• Repeat with the final layer.
   
• Let the cake layers cool in their sheet pans on wire racks for 5 minutes, and carefully turn them out onto a new parchment paper. Peel off the paper liners and let cool completely while you prepare the silky smooth buttercream.

Direction for Silky Chocolate Buttercream

 

• Take your butter out of the fridge for about 20 minutes before making your chocolate buttercream. For this frosting, you want your butter to be semi-cold. Semi-cold butter should still be cold to the touch, and you should be able to make a slight imprint with your finger, but it should not feel greasy! In the summer use cold butter straight from the fridge.
   
• In a medium heatproof bowl set over barely simmering water, melt the 150-gram chocolate, occasionally stirring until the chocolate is completely melted!  If you melt the chocolate in the microwave, use a microwave-safe bowl, and microwave for 20 -seconds intervals. Allow the chocolate to cool to room temp.
   
• Put the 175 gram sifted powdered sugar, 180-gram semi-cold salted or unsalted butter ( cut into small cubes), 1 teaspoon instant espresso powder, and 1 teaspoon vanilla bean paste into a food processor and pulse on high speed until smooth about 1 to 2 minutes.
   
• Scrape down the sides and bottom of your bowl, add the melted and slightly cooled chocolate to the food processor, and pulse on high speed until silky smooth, about 1 minute! 
   
• Once the chocolate buttercream is silky smooth, Add the 40-gram cold heavy cream and blend at high speed for 1 minute more! It is now ready!
   
•  Your chocolate buttercream is now ready, use immediately for ideal spreading consistency.
   
• If you feel that the chocolate buttercream is too soft, refrigerate the frosting until it firms up just slightly. About 5 minutes, more if needed!
   
•  If not used right away, store it in an airtight container in the refrigerator for up to 3 days. When ready to use, bring to room temperature and pulse in your food processor to bring back to a spreadable consistency, or use your stand mixer and whisk attachment.

Directions for the Salted Caramel Sugar

•  I use the dry-burn technique; I don't add water to the sugar before putting it on the heat; caramelizing dry sugar means it goes faster, but you have to watch it more closely. Don't touch the sugar until there is a full layer of melted and browning liquid sugar on the bottom, with a smaller layer of unmelted white sugar on top. When the edges of the melted sugar begin to darken, you can use a wooden spoon to bring them into the center to help melt the unmelted sugar. Continue stirring and pushing the sugar around until it is all melted and evenly amber in color.
   
• For this recipe, you need a blender or a food processor.
   
• Sprinkle 250-gram sugar evenly over the bottom of a heavy saucepan and set over medium-high heat, standing by with a wooden spoon or a heatproof spatula.
   
• When you see a layer of melted sugar underneath the unmelted white sugar in the center of the pan, Mix the sugar continuously with a wooden spoon until it has completely melted ( no visible granules) and is dark golden-brown. As you are stirring, break any sugar clumps apart with the wooden spoon. The entire process should take 5 to 7 minutes.
   
• The color of the caramel sugar will determine the depth of the caramel flavor.  The trick is to cook the caramel to a dark amber brown color, so the caramel flavor is intense and has that wonderful intense salted caramel flavor. But don't let it go too far, though, or it will taste burned.
   
• Remove from heat and carefully pour the melted sugar to a medium baking sheet, spread it out evenly into a thin layer.
   
• Sprinkle with a pinch of sea salt ( more or less) and let the burnt sugar cool completely at room temperature.
   
• Once the salted caramel shards are completely hardened, about 30 to 60 minutes, cover the top of the baking sheet with aluminum foil, then tap the sheet pan on the counter, so the caramel shards come in many small pieces.
   
• Place the crushed caramel shard pieces into the food processor. Make sure your food processor or blender is completely dry on the inside. Otherwise, you will get a sticky mess.
   
• Add 1 tablespoon corn starch, Cornstarch is important as it keeps the sugar dry. Otherwise, you get a sticky mess.
   
• Blend a few minutes until it looks like powdered sugar. 
   
• Run it through your fingers to feel the sandy texture, and keep blending until you are satisfied.
   
• Store your Homemade caramel ( powdered) sugar in an airtight container and store it in a cool, dry spot at all times, and it will keep indefinitely.

Directions for the Toffee Whipped Cream

• Before you start, the colder the cream is the easier and more successful it will whip and create the lightest whipped cream.  For best results take the cream out of the fridge and chill the cream in the freezer for 15 minutes before you start. If you don't have a freezer just make sure your cream is really cold,  a slightly warm cream does not whip up well.
  
   
• Use a scale to weigh the right amount of caramel sugar you prepared. If your preference is less sweet, use less caramel sugar. I prefer using 150 to 200 grams salted caramel sugar.
   
• In a large bowl, using an electric beater ( or use a bowl of your stand mixer fitted with the whisk attachment), add 500 grams cold cream and 1 or two teaspoons vanilla bean paste.
   
• Whip the cream at low speed for one minute. Then add a large spoonful of salted caramel sugar into the cold cream, a tablespoon at a time. If you dump all of the caramel sugar at the same time, you will get a lot of large toffee pieces in this frosting, it is up to you how you like it.
   
• Continue whipping the cream at medium-low speed until it is fluffy and holds a stiff peak, do not overmix, or it gets grainy.
   
• If you feel the frosting isn´t stable enough after you whisk it, I recommend you continue whisking by hand ( using a spatula) to thicken it to stiff peaks (10-20 seconds)
  to make sure you don’t overmix it, check it a few times while you whisk it together if it is fluffy enough.
   
• Place in the fridge until needed.
   
• When frosting the cake layer with the toffee whipped cream, be careful not to run your spatula over the whipped cream too many times, or you´ll overwork the cream and it´ll become grainy.
   

Assembly the cake

 

• Place the cooled almond cake layer on a baking sheet or cake board, Place all of the silky smooth chocolate buttercreams on top of the first cake layer. Use a spatula or palette knife to spread into an even layer. 
   
• Then place the first cooled chocolate sponge cake layer on top, press the cake down lightly to help it stick to the chocolate buttercream.
   
• Next place the Toffee Whipped Cream on top of the second cake layer, Use a spatula or palette knife to spread into an even layer. 
   
• Place the final chocolate sponge cake layer on top, Press down lightly to help it stick to the toffee whipped cream.
   
• Cover the cake with plastic wrap, place a light book or magazine on top for the cake layers, and place the cake in the fridge for at least 4 to 6 hours, preferably overnight.
   
• The next day; Make another batch of silky smooth chocolate buttercream, optional 
   
•  Take the cold cake out of the fridge, remove the plastic wrap, and Place all of the silky smooth chocolate buttercream on top of the first cake layer. Use a spatula or palette knife to spread into an even layer. 
   
• Cut into small slices and enjoy. 
   
• Keep leftovers in the fridge for up to 3 days.