Preheat your oven to 180°C/350°F/gas mark 4.
Grab the chocolate and break it into pieces. Carefully melt in a heatproof bowl over a pot of simmering water on a low heat. Then leave to one side.
Place the coconut oil and sugar in the food processor and cream together for a few minutes. Separate the eggs into yolks and whites. Pour the yolks into the food processor, along with the grated beets, melted chocolate, ground almonds, vanilla seeds and salt. Process until well combined and pour the mixture into a large bowl.
In another bowl whisk the egg whites until fluffy. Fold the whites into the chocolate mixture and stir gently to keep them nice and airy.
Grease a 21cm cake tin with coconut oil. Pour in the cake batter then pop into the oven. Bake for 20 minutes, then remove and leave to cool in the tin for 10 minutes.
Melt 150g of chocolate in a heatproof bowl over a pot of simmering water on a low heat. Pour the chocolate over the cake and decorate with berries.