This recipe is a family fave! My mom would make this for every special occasion and I have so many tasty memories of it. Obviously her version was full of eggs and butter, but I figured out a way to substitute these things without compromising on texture. The texture in this 4 layer cake is key, because the cake needs to be uber light and airy. I used a lot of aqua faba in the batter to get it this way, but it was the perfect swap!
The cake batter recipe as written makes 2 layers. You'll need to double the recipe, but do it separately, for a 4 layer cake. And it is necessary to make a 4 layer cake. The 2 layers just don't cut it as the cakes are pretty thin! So ensure you roast 2 cups of hazelnuts in advance so you're ready to go. Also 1 cup of whole hazelnuts is just slightly more than 1 cup of the ground hazelnuts. Ensure you measure everything correctly for this recipe!
** serves 8 people
cake ingredients (for 2 layers):
1 cup ground hazelnut meal/flour (roast 2 cups whole hazelnuts total)
3/4 C aqua faba (from 1 x 19 oz can of chickpeas)
3/4 C + 2 tbsp all-purpose flour
1 tsp baking powder
1/4 tsp baking soda
3/4 cup granulated sugar
1/2 tsp cream of tartar
1 tsp vanilla extract
2 tbsp vegetable oil
buttercream filling ingredients:
4 tbsp vegan butter, softened to room temperature
1 tbsp instant espresso
3 tbsp water
2 1/2 C confectioners sugar, sifted
1 tsp vanilla extract
mocha coconut whip ingredients:
2 3/4 C coconut cream (about 2 cans coconut cream refrigerated for at least 36 hours)
2 tbsp cocoa powder
2 tbsp confectioners sugar
1 tsp vanilla extract
Pre-heat oven to 400°F.
Place 2 cups of whole hazelnuts on a baking sheet in an even layer. Bake for 10 to 12 minutes until the skins are very cracked and much darker in colour. Let cool.
Lay out hazelnuts onto a clean tea towel. Gather the towel over the nuts and rub together with your hands. The skins will peel right off. If they don't they probably aren't roasted enough so place them back in the oven. You want to get as much of the skin off as possible, but some remnants are fine. They make the cake bitter if not removed and roasted.
Place cleaned hazelnuts into a food processor and whiz into a fine meal You will have just over 2 cups ground. You'll use the excess amount to dust the top of the finished cake!
Measure the aqua faba exactly to 3/4 cups into a glass bowl. Place it in the fridge or freezer to chill. It should get really cold but not frozen or have any ice chips in it.
Change oven temperature to pre-heat to 350°F.
Prepare 2 (8-inch) cake pans by greasing them with vegan butter or shortening. Trace the circumference of the cake pan onto parchment paper and cut out 2 circles. Place these into the bottom of each pan, flattening it out to the edges with your fingers.
Add 1 cup hazelnut meal/flour to a mixing bowl with all-purpose flour, baking powder, baking soda, and granulated sugar. Stir to combine and set aside.
Beat the chilled aqua faba for about 2 minutes or up to 4 or 5 minutes until foamy and white (soft peaks). Add cream of tartar and continue beating until stiff peaks form, about another 3 to 5 minutes.
Add in vanilla extract and continue beating for another minute or so while you drizzle in the vegetable oil. You'll notice the meringue get thicker and shiny. It will have quadrupled in volume.
Fold the dry ingredients into the meringue gently with a wide spatula until just combined. Do not over mix.
Divide the batter between both cake pans and spread out in an even layer to the edges with a spatula. Shake it side to side and tap it gently onto the counter to ensure it's even.
Bake for 20 to 25 minutes at 350°F or until a toothpick comes out clean. Once baked remove the cake pans onto wire racks to cool for 15 minutes. Take a thin knife or icing spatula and run it around the edge of the cake. You should notice that the cake has already slightly come away from the edges of the pan, but go around once more to ensure it's not sticking. Place the wire rack on top of one cake pan and flip it over gently tapping it if necessary to remove the cake. Remove the parchment paper on top and allow cakes to cool completely before icing and assembling.
Don't forget! You'll need to repeat this process for the other 2 layers of the 4 layer cake! You can also make the cakes a day ahead and then frost and assemble on the day of serving. Once cooled you can store the layers of cake between parchment paper in a container or on a plate covered in the fridge overnight.
For the buttercream filling combine the water and instant espresso together. You could also you 3 tablespoons of strong brewed coffee or espresso rather then mix the instant powder. Then beat the softened vegan butter until smooth with a hand mixer or in a stand mixer. Add 1 cup of confectioners sugar and continue beating. While beating add in half the coffee and vanilla extract. Then add in more sugar while still beating the frosting and continue adding the remaining coffee and sugar in portions while beating the mixture together until it's well combined and smooth. It should form a frosting that's the consistency of pudding. It's not super thick or stiff.
Place one cake layer on your cake platter or serving dish top down. Then take a third of the buttercream and spread it out to the edges in an even layer with an icing spatula. Add another cake layer top side up and ice another layer on top. Then add your third cake layer top side down and repeat with the remaining frosting. Then add your final layer top side up.
Refrigerate the cake while you prepare the mocha coconut whip. If any filling is dripping down the sides of the cake just use your spatula to spread it around the edges, once refrigerated it will become a little more solid and stick and then you're covering it up with the whip all around the outside anyway.
To make the mocha coconut whip you need to use only the thick cream from cans of coconut cream or full-fat coconut milk. It's best if you can refrigerate the cans for at least 36 hours. Sometimes I find overnight doesn't get it separated enough. Because of how much you need for this it's best if you can find coconut cream in a can as it's mostly all the thick stuff with very little liquid!
Scoop out the thick cream without any liquid getting into the mix and place it all in a cold glass mixing bowl. Whip it for a few minutes with a hand mixer until smooth and fluffy. Then add the cocoa powder, confectioners sugar, and vanilla extract and continue to beat together until smooth and well combined.
You'll use all of this coconut whip to frost a thick layer all around the cake. This does take some practice but using a large icing spatula for the majority of the frosting works best and then get in with a smaller icing spatula to get the bottom edge nice and smooth. You can clean the edges of your cake platter with a damp cloth once you're done frosting the cake.
Decorate it as you wish, but I added shaved dark chocolate and more of the ground hazelnuts to the top! Keep the cake refrigerated until serving.