• Preheat an oven to 180°c/160°c fan (355°f/320°f).
• Grease & line a 6" x 8" Battenberg tin with baking parchment (see notes).
• Place the sugar into the bowl of a stand mixer then rub in the lemon zest. Add in the softened butter then use the paddle attachment to beat until light & fluffy, around 4-5 minutes.
• With the mixer running on a medium speed, beat in the eggs one at a time.
• Sift together the flour, salt & baking powder then fold into the batter along with the ground almonds, vanilla & almond extract.
• Once mixed, fold in the lemon curd.
• Transfer the cake batter into your lined baking tin & smooth the top over with a palette knife.
• Place the tin onto a baking tray & bake in the preheated oven for 25-30 minutes or until risen & a skewer inserted into the cake comes out clean.
• Leave to cool in the tin for 30 minutes then use a sharp, serrated knife to trim the top of the cake so that it is level with the top of the tin.
• Carefully remove the cake from the tin then peel off the baking parchment & transfer to a wire cooling rack to cool completely.
• Once cool, place the cake in the fridge for 20-30 minutes.

  This makes trimming the cake easier!

Marzipan Layer

• If necessary, use a sharp, serrated knife to give the top of the sponge another trim, making sure to keep it flat.
• Next, dust a worksurface with icing sugar then using a rolling pin, roll the marzipan out into a large rectangle. It should be slightly bigger than your cake & around 3mm thick.
• Gently warm the apricot jam up, to soften (in the microwave or on the stove) then brush over the top of the sponge.
• Brush off any excess icing sugar from the marzipan then carefully place on top of the sponge, pressing down lightly to stick (the marzipan should overhang the cake's edges slightly).

  Return the cake to the fridge for another 20-30 minutes, whilst you make the buttercream.

Buttercream

• Place the softened butter & vanilla paste into the bowl of a stand mixer & beat with the paddle attachment until fluffy & well combined, 1-2 minutes.
• Next, add in the sifted icing sugar & salt then mix to combine.
• Pour in the milk & mix on a medium speed until the buttercream is light & fluffy.
• Transfer half of the buttercream to a piping bag & half to a bowl then set aside.

Buttercream Layer

• Take the cake out of the fridge & trim the edges so that the sponge & marzipan are level.
• Next, cut the sponge into 3-4cm wide squares. You should get at least 12. Place the cakes onto a lined baking tray.
• Using a palette knife, spread a thin, even layer of buttercream over the 4 vertical sides on each square of cake.
• Cut the end off the piping bag & pipe a 1cm wide blob of buttercream on top of the marzipan on each cake. Use a finger to smooth out the buttercream, if necessary.
• Return the cakes to the fridge for 15-20 minutes, to set the buttercream.

Fondant Icing

• Place the sifted fondant icing sugar into a mixing bowl, along with the lemon juice. Add in 2 tbsp of cold water then whisk to make a smooth, thick icing.

  If the icing is too thick, whisk in more water, a little at a time. It should be thick but still pourable.
• Add in enough yellow food colouring, to turn the icing a vibrant yellow colour then set aside.

Icing

• Line a baking tray with baking parchment then place a wire cooling rack on top.
• Transfer the cakes to the cooling rack then pour fondant icing over each one, so that they are coated in a thick layer. Leave to set at room temperature.

  You might need to give the cakes a second coating of icing, to get a good, thick layer. Make sure the first layer is set before pouring over more icing.

  If you need to reuse any icing, carefully lift the baking paper off the tray & pour the icing back into the bowl it came from.
• Whilst the icing is setting, warm the dark chocolate up (in a microwave or over a bain marie) until just melted then leave to cool slightly.
• Once the fondant icing has fully set, transfer the cooled, melted chocolate to a piping bag then pipe thin lines over the top of each cake. Leave to set then transfer the cakes to a plate, to serve.