3. Blend the date mixture with the ground nuts and the grated beetroots in a large bowl.
4. Add the coconut, cacao powder and psyllium husks to the bowl and stir them in until blended with the date and nut mixtures.
5. Scrape the blended mixture back into the bowl of the food processor and pulse until the ingredients are well combined and finely textured.
6. Line a cake tin with baking paper and spread the batter evenly over the bottom. Refrigerate for about 15 minutes or until firm to the touch.
To make the icing
1. Gently melt the cacao butter in a small saucepan then allow it to cool.
2. Combine the cashews, cacao powder, maple syrup, lemon juice and tamari in the bowl of a food processor or Vita-mix blender and process until the nuts are well ground.
3. With the motor running, pour in the melted cacao butter and blend until the mixture is smooth.
4. Spoon the icing over the cake and refrigerate until the icing is set, about 15 minutes.