Preheat oven to 180 degrees C. Grease baking trays. Sift together the flour, baking powder and salt; set aside;
In a medium bowl, cream together the butter and brown sugar. Beat in the banana and egg, then stir in the vanilla. Gradually stir in the dry ingredients until well blended. Fold in the chocolate chips. Drop by rounded spoonfuls onto the prepared baking trays.
Bake for 8 to 10 minutes in the preheated oven. Allow biscuits to cool on baking tray for 5 minutes before removing to a wire rack to cool completely.