Line the base and 5cm of the side of your slow cooker with foil to create a kind of cake tin, then line the foil with baking parchment. Mash the bananas in a bowl until broken down, then set aside.

Beat the butter and both sugars together until light and creamy, around 5 mins. Beat in 1 egg with a spoonful of the flour until combined. Repeat until all the eggs have been incorporated.

Fold in the remaining flour and baking powder followed by the mashed banana. Tip into the slow cooker, put the lid on and cook on high for 4 hrs. Don’t remove the lid for at least 3 hrs 30 mins, then check to see if it’s done. A skewer inserted into the middle should come out clean. If not put the lid back on and cook for another 15 mins, then check again. Turn out onto a board and leave to cool before serving with a little butter, or just as it is.