Cookies are widely consumed ready to eat and convenient foods throughout the world by people of all ages which gives more nutrients than any other single food source. In fact, they represent the largest category of snack foods in most parts of the world. Generally cookies are recognized as flat hard and crunchy foods. Traditionally the process of cookies making fairly simple with basic ingredients consists of flour, eggs and sugar.

They are usually made from soft wheat, a cereal, which is cultivated in many parts of the world, but imported by countries with unfavorable climatic conditions. Therefore to produce baked goods, regions with limited supplies of wheat flour must rely on imports or exclude wheat products from the diet. Due to the high cost, geographical scarcity and high demand of wheat flour, strong initiatives are taken toward the provision of alternative source of flour. It is therefore of economic advantage if wheat import can be reduced by substitution with other nutrient dense materials. This led to the whole idea of composite flour.

Composite flour has been defined in numerous researches as a combination of wheat and non-wheat flours for the production of leavened breads, other baked products such as biscuits, cookies, and pastas. The substitute should be one that is readily available, cheap and able to replace wheat flour in terms of functionality. In the quest for a wheat substitute, flour with better nutritional quality than wheat would be highly desirable, especially in developing countries where malnutrition is prevalent. It provides an excellent means of improving the nutritional quality (protein, minerals, vitamins, and bioactive compounds) of foods through incorporation of less expensive non-wheat flour for food product enrichment. Banana (Musa sapientum L) is one of the major fruit crops in Bangladesh in respect of production and area. It is one of the economically important fruit crops grown in Bangladesh both in homestead and commercial farms. It is available throughout the year and consumption rate is higher than any other fruits. It is one of the cheapest, delicious and most nourishing of all fruits. Banana is highly nutritious and easily digestible than many other fruits. Bananas are popular for aroma, texture and easy to peel and eat. Banana is a rich source of calories, as well as most of the vitamins essential for human nutrition. Bananas are also rich in carbohydrates, potassium, and vitamins including A, C and B6 and good source of fat free dietary fiber.

The increasing interest to find new sources of dietary fibres with specific bioactive constituents may add new beneficial properties to the traditionally commercialized products. Currently peels of variety of fruits get focused as natural source of antioxidant and dietary fibre. With these grounds, banana peel has attracted attention as recent reports suggest it as a very good source of dietary fibre and antioxidant. Besides, banana peel is a rich source of high total starch (73. 4%), resistant starch (17. 5%) and dietary fiber content (14. 5%), protein, fat and micronutrients). Due to the high content of these functional ingredients, regular consumption of green banana flour can be expected to confer beneficial health benefits for humans.

New economical strategy to increase utilisation of banana includes the production of banana flour when the fruit is unripe, and to incorporate the flour into various innovative products such as slowly digestible cookies, high-fibre bread and edible films. There are previous studies that had been enhanced the nutritional quality of cookies by utilizing different composite flour from various types of food sources in cookies.