Sift the flour and baking powder in one bowl.
Add the essence, granulated sweetener and mashed bananas.
Add 2 of the eggs and mix well.
Separate the other 2 eggs and add the yolks to the mixture mixing again.
Whisk the 2 whites until very stiff and gently fold into the mixture.
Pour into a lined silicone loaf tin (2lb) sprayed with low calorie cooking spray and sprinkle the chocolate chips evenly over the top.
Cook in a preheated oven at 180°C for 40 minutes.