Lightly grease a 30 x 23cm (12 x 9in) traybake or roasting tin and line it with non-stick baking parchment, leaving some overhang up the sides to make lifting the cake out easier. Preheat the oven to 180°C/350°F/Gas Mark 4.

In a large bowl, cream the butter and sugar together using an electric whisk for 2–3 minutes until light and fluffy.

In a separate bowl, mash the bananas. Gradually add the mashed bananas and eggs to the creamed butter and sugar, whisking together with the electric whisk until well combined.

Sift in the gluten-free flour and baking powder, then gently fold everything together using a spatula or wooden spoon.

Pour the mixture into the prepared tin, level the surface, and bake for 35–40 minutes, or until the cake has shrunk slightly from the sides of the tin and springs back when pressed lightly in the centre.

Once baked, leave the cake to cool completely in the tin. Then lift it out using the parchment, peel off the paper, and place on a wire rack ready to decorate.

For the icing: Put the butter in a bowl and whisk for a few minutes until pale and fluffy.

Gradually add the icing sugar, mixing well between each addition until smooth. Near the end, add in the milk and vanilla extract and whisk until combined.

Spread the icing evenly over the cooled cake using a palette knife. Finish with a generous drizzle of caramel sauce—warm it gently in a bowl if needed—and scatter over some banana chips for decoration.