Preheat the oven to 170 degrees Celsius.

Peel and chop the sweet potato into small cubes.

Place into the top of a double steamer with water in the bottom saucepan. Place the lid on top and bring to the boil. Steam until the sweet potato is tender and easily broken apart with a fork.

While the sweet potato is cooking add the cacao butter to a small saucepan on a very low heat.

Continue stirring the cacao butter until completely melted and then add the cacao and cashew butter. Whisk until smooth.

Add the coconut oil and maple syrup to the cacao butter mixture, whisk and then set aside.

Place the sweet potato into a food processor and process until it resembles a very smooth puree.

In a mixing bowl combine the almond meal, baking powder and coconut sugar (if using).

Pour in the sweet potato and chocolate mixture and mix until well combined.

Tip the brownie mixture into a baking paper lined slice tin and bake in the oven for 30 minutes or until the brownie springs back when gently pressed in the centre.

Remove from the oven and allow to cool for 10 minutes before slicing.