Place the chocolate and butter in a thin-sided bowl, suspend the bowl over the gently simmering bain-marie, ensuring that the bowl does not touch the water. Melt the chocolate and stir until smooth.
Place the egg yolks and sugar in a bowl. Using the whisk on a hand mixer, beat for approx. 5 mins. until the mixture becomes lighter in colour. Stir in the beetroot and chocolate. Beat the egg whites with the salt until stiff, gradually add the sugar, continue to beat until the egg whites are glossy. Mix the almonds, raspberry, beetroot and baking powder, carefully stir into the chocolate mixture along with the egg whites. Transfer the batter to the prepared tin.
Approx. 50 mins. in the lower half of an oven preheated to 180°C. Remove from the oven, allow to cool slightly, remove the tin frame, slide onto a cooling rack and leave to cool completely.
Heat the cream then remove the pan from the heat. Add the chocolate, melt, and stir until smooth. Pour the glaze over the cake so that it runs over the sides, leave to dry. Dust the cake with the reserved berry and beetroot powder.