Okay, it's not going to win any health food awards, but as a once in a while treat, this is a pretty good option in my opinion. My recipe is adapted from the 30-minute-healthy-chocolate-cake recipe which can be found on: https://scrummylane.com/30-minute-healthy-chocolate-cake/
150 g sweet potato, cooked in the microwave then mashed. 125 g self-raising flour 45 g cocoa powder 1/4 teaspoon salt 1/4 teaspoon bicarbonate of soda 3 eggs lightly whisked 1 teaspoon vanilla extract 60 ml olive oil 120 ml maple syrup
Preheat the oven to 355F/180C. Line the bottom and sides of a 23cm round cake pan with baking paper. My son rubbed a little butter all over the pan first to help the paper stick. This produces quite a thin cake - similar to a brownie. If you prefer a thicker cake, use a smaller tin and increase the cooking time slightly. Peel the sweet potato and then prick it all over with a fork.
Place it in a microwavable container and cook for 2 minutes before turning it over and cooking for 2 minutes more. Check the potato is soft enough to mash, cook for a bit longer if not.
Mash with a fork and leave to cool.
Measure the flour, cocoa powder, salt & bicarbonate of soda and combine in a large bowl.
In another bowl, add the eggs, vanilla, oil and maple syrup, stir to combine.
Add the sweet potato to the wet ingredients and mix well with to remove as many lumps as possible.
Make a well in the centre of the flour and pour the wet ingredients into it. Mix again until well combined.
Pour the batter into the prepared baking pan and bake for 12 minutes or until a skewer comes out clean from the centre.
Let cool for 10 minutes in the pan, then carefully turn out onto a wire rack to cool completely.