Peel the sweet potato and cut into cubes. Add the sweet potatoes to a pot and cover with boiling water. Boil for 15-20 minutes until the sweet potatoes are soft throughout. You can also steam the sweet potatoes.
Add the sweet potatoes to a food processor and blitz until smooth in texture. You can also add the sweet potatoes to a bowl and mash with a potato masher until smooth.
Add the rest of the ingredients and blitz until everything is mixed well.
Pre-heat the oven to 180 degrees Celsius (355 Fahrenheit). Add the brownie mixture to an 8 x 8 inch (20 x 20 cm) baking tray or to a regular baking tray lined with parchment paper.
Use a spatula to spread the mixture evenly in the baking tray.
Bake for 25 minutes. To check if the brownies are cooked you can pierce with a toothpick and if the toothpick comes out without any wet brownie mixture sticking to it, then the brownies should be good to go.
Remove from the oven and leave to cool before cutting into slices.