In a medium bowl, mash the banana using a fork.
Sift in the flour, then add the sugar, salt and yeast. Pour in the milk and stir to combine.
Cover the bowl with cling film or a tea towel and place in a warm spot. Leave the mixture for about 45 minutes or until bubbly and doubled in size.
Heat a little oil in a medium frying pan over low heat. Add a ladle of batter and fry until the top of the pancake begins to bubble, then flip it over and cook until both sides are golden brown.
Repeat until all the batter is used up.