Now sometimes you can get away with it, but I must say that when a recipe tells you to use a specific cake tin, my advice would be to stick to that tin! I have been able to use different tins from those suggested in recipes in the past, but this time it did'nt really work out for me.
Having three bananas going quite brown I thought the best thing to make would be Banana Bread. I would usually use a long tin like the recipe suggests, but being a student all my tins are at home and all that is left here, in my 'student' kitchen is a square tin and a 22 cm round cake tin. But I still thought it might turn out ok if I used the square tin. But, disaster struck and now I have been left with a thin and fairly tough banana cake, although it does still taste amazing. The moral of the story is, that unless you are 100% it will all work out ok or you are an extremely experienced baker,I would suggest that you should probably just stick to what the recipe tells you to use.
Either way here is the recipe for the Banana Cake, it is simply amazing and freezes really well.
200gr self raising flour
1/2 tsp baking powder
pinch of salt
170gr soft brown sugar
3-4 large bananas
100gr chopped walnuts
(The tin that I would recomend for this recipe would be a medium sized loaf tin, about 21.5 cm x 11.5 cm)
1) Cream the butter and sugar together
2) Gradually add the eggs, beating well after each addition.
3) Mash the bananas to a pulp and gently fold them into the butter mixture.
4) Sieve the flour, b. powder and salt into the butter mixture and fold into the butter mixture.
5) Finally fold in the walnuts( I personally like to leave the walnuts quite chunky rather than cut them into little pieces)
Pour the mixture into the greased and lined tin and bake at 180C, 160C fan oven, gas mark 4, for 1 hour and 15 minutes, just until a cocktail stick comes out clean.
I dont usually frost or decorate this cake with anything as it is meant to be a tea time treat, but you could make a nice buttercream frosting adding a little bit of maple syrup to give it a nice colour and depth of flavour, or simply drizzle some royal icing over(made by mixing icing sugar with water.