Put all the ingredients except the Biscoff spread in a large bowl and mix together using an electric whisk for 3-4 minutes, until well combined with no lumps.
100 g butter, 175 g caster sugar (superfine sugar), 2 medium eggs, 2 bananas, 225 g self-raising flour, 1 tsp baking powder, 1 tbsp milk
Place the cake mix in a lined 2 lb loaf tin.
Using a large spoon, dollop the Biscoff spread on top of the mix and marble it together using a skewer.
150 g Biscoff spread
Bake at 180℃ / 350℉ for around 45 minutes, or until a skewer comes out clean.
Leave to cool in the tin. Remove when cool and serve.
Notes
Serve for a naughty breakfast, for a tasty treat, or with a cup of tea.