The perfect baked cookie is the result of precise ingredients and measurements in its recipes. For those who want a lower fat option or are just out of eggs, several substitutes exist for eggs in cookie recipes. However, bananas consistently provide the best density similar to eggs in most cookie recipes. Cookies will come out of the oven moist and flavorful, though they may not be as brown as those baked using a traditional recipe

Cream the sugar and butter with a beater as you would in a standard cookie recipe until the mixture is light and fluffy.

Add one pureed banana for every egg required in the recipe. For example, if your recipe requires three eggs, add three pureed bananas to the creamed sugar and butter. Mix thoroughly with a spoon.

Add the additional dry ingredients such as the flour, baking powder, salt and chocolate chips. Complete the recipe as usual.

Bake the cookies at the oven temperature required for the recipe. However, you may need to bake them longer for an additional 10 minutes since the bananas have extra moisture.