Prepare the tin and oven – Grease the cake tin well and line it with baking parchment, leaving an overhang for easy removal. Preheat the oven fully so the cake bakes evenly from the start.

Mash the bananas – Mash the ripe bananas until mostly smooth, keeping a few small lumps for texture. Very ripe bananas add natural sweetness and moisture.

Mix wet ingredients – Add the caster sugar, eggs, vegetable oil, milk, and vanilla extract to the bananas. Whisk gently until everything is well combined and smooth.

Combine dry ingredients – In a separate bowl, mix the self-raising flour and baking powder so the raising agent is evenly distributed.

Bring the batter together – Fold the dry ingredients into the wet mixture gently. Stop mixing as soon as the batter is smooth to avoid a dense cake.

Fill the tin – Pour the batter into the prepared tin and level the surface lightly so it rises evenly.

Bake until just set – Bake on the middle shelf until the cake is well risen, lightly golden, and a skewer inserted into the centre comes out clean.

Cool properly – Leave the cake in the tin for about 10 minutes, then lift it out and cool completely on a wire rack before slicing.