Break the chocolate into pieces, place in a food processor and blitz until crumbed (not powdered). Tip out into a small bowl.
Put the beetroot in the food processor and whiz to a purée.
Add all the remaining cake ingredients, whiz until well mixed, and stir in the chocolate pieces.
Preheat the oven to 180C/Gas 4.
Pour the cake batter into the prepared cake tin and level out the surface.
Bake for 45-50 mins or until a skewer inserted into the centre comes out clean (the surface of the cake may have cracked a little).
Allow to cool for a few mins in the tin before removing to a cooling rack.
For the buttercream, put the butter in a mixing bowl and beat until creamy.
Add the icing sugar, cocoa powder, cream, salt and vanilla extract and beat together (add more icing sugar or cocoa powder if it’s too thin, or more cream if too thick).
Cut the cake in half horizontally and sandwich the two halves together with a third of the icing, then spread the rest on top and over the sides.
Decorate as you wish – we used a few pumpkin seeds, almond halves, dessicated coconut and dehyrdrated berries.
Recipe by appetite magazine at https://www.appetitemag.co.uk/beetroot-chocolate-dream/