Makes 1 four-layer cake
Easy
1 hour, plus chilling time
30 minutes
Preheat the oven to 160°C.
Line 2 x 18 cm cake tins with parchment paper and brush the surface with oil.
Beat the egg whites with the vinegar until soft peaks form.
Mix the egg yolks, almond flour, agave syrup, bicarbonate of soda and vanilla extract, then whisk until light and creamy.
Gently stir 1/4 of the almond batter into the beaten egg whites. Fold the remainder of the almond batter and the grapeseed oil into the egg whites.
Divide half the batter between the prepared tins and bake for 30 minutes, or until the surface springs back from a light touch and a skewer inserted comes out clean.
Allow to cool and remove from the cake tins. Make another 2 sponge layers in the same manner.
Place one layer of cake on a serving plate and spread 1/3 of the caramel over the cake, then 1/3 of the lemon cream. Repeat with 2 more layers, using up the remaining caramel and lemon cream, then top with the remaining layer of cake. Cover the cake completely with clingfilm and chill for at least four hours or overnight.
To make the honey-nut caramel, place the agave syrup in a small frying pan and heat over medium-low heat, stirring constantly, until it starts to foam. Stir in the roasted almond butter and vanilla extract and simmer, without stirring, for another minute until large bubbles form and the mixture pulls away from the sides of the pan slightly. Remove from the heat and allow to cool.
To make the lemon cream, suspend a heatproof bowl over a saucepan of simmering water, then add the egg yolks, agave syrup, lemon juice and zest and salt. Whisk constantly until very thick, or until the mixture reaches 80°C on an instant-read or sugar thermometer. Remove from the heat and allow to cool to 60°C.
Transfer to a blender and blend at high speed, adding the coconut oil a little at a time. Pour the lemon cream into a container, press a piece of clingfilm onto the surface to create an airtight seal and chill for at least 4 hours or overnight.
To make the Swiss meringue topping, suspend a heatproof bowl over a pan of simmering water. Add the egg whites, xylitol and salt and whisk constantly until the xylitol has dissolved and the egg whites are warm to the touch (test by rubbing the mixture between your fingers).
Transfer the mixture to the bowl of an electric mixer fitted with the whisk attachment and beat, starting on low speed and gradually increasing to high, until stiff, glossy peaks form, about 10 minutes.
Add the vanilla and mix until combined. Use immediately.
Remove the clingfilm from the cake and spread the meringue all over, using a spatula or a spoon to create dramatic swirls.
Cook’s note: For the special celebratory version of this cake, you need to make four sponge layers. It is advisable to do so in two batches. The quantities for the fillings and topping given below are sufficient for a four-layer cake.
