•  Preheat the oven to 160C. Grease and line the cake sandwich tins.
• Combine the butter, sugar and vanilla in a stand mixer until fluffy. Gradually add the 6 eggs one at a time, beating in between each addition.

   
• Melt the chocolate in a microwave (only 30 seconds at a time, we don't want the chocolate to seize) or in a bowl over a pan of hot water (the bain marie method). 
• Add the melted chocolate and continue to beat. Pour in half the flour, combining lightly.
• Add the rest of the flour. Divide between the 2 tins, around 700g each. Bake for 45 minutes. 
•  Remove the cake tins from the oven and let them cool.  

For the buttercream:

• Beat the butter until fluffy, then add the icing sugar. Add a little milk to loosen.  
• Use a palette knife or butter knife to spread the buttercream to sandwich together the chocolate cakes. 
• Use a thin layer of the buttercream to spread a 'crumb coat' over the rest of the cake, doing the sides first so you can spin it around by holding the top. Add the 'crumb coat' to the top.  A crumb coat is a very thin layer of icing or buttercream that allows the second coat to adhere.

For the ganache:

• Melt the chocolate and cream together in the microwave (30 seconds at a time) or use the bain marie method. Stir until well combined.

Putting together the cake:

• With a sharp serrated knife, thinly slice off the top of each cake so that they fit together. If the sides are uneven, use the knife to trim round. 
•  Finally, using the palette knife, spread the ganache over the sides and top of the cake. Leave the ganache to dry for a few minutes, then scatter the violet sugar over the top of the cake. Add the crystallised violets around the cake. Stud the sides with the violet pearls. 

Optional: add a large purple flower to the middle of the cake.