Preheat oven to 190͒C, and line a square cake tray with baking paper

Cut sweet potato into evenly sized chunks, add to a medium sized pot with enough water to cover the sweet potato. Cover with a lid, and steam until they are very easily pierced with a fork. Allow to cool slightly once finished cooking, and mash well with a fork

In a medium sized bowl add the eggs, brown sugar, olive oil, milk and vanilla essence and stir until well combined

Add the crushed weetbix, mashed sweet potato, plain flour and baking powder to the wet ingredients and stir until well combined

(Optional) Gently stir in chocolate chips until evenly distributed

Pour mixture into the lined baking tin and cook in the preheated oven for 40 mins, or until a clean knife or skewer comes out clean