Making soft, moist cookies it not all that hard but it requires that you use the right recipe with the correct ingredients. Once you have baked your cookies, keeping them moist is a whole other issue and if not handled correctly can turn those soft chewy gems into hard dry hockey pucks in no time at all.
Review the recipe
When you are choosing your recipe, look for one that promises moist, soft cookies. You will find that many recipes state that they produce crispy cookies which some people prefer. Follow the recipe exactly as written, at least the first time. Once you have determined that it produces the texture of cookie that you are looking for, then you can experiment with adding your own touches to the recipe.
Certain ingredients are important to the moistness and softness of cookies. When it comes to butter, it is better added to recipes cold than melted for the purposes of moistness. Most recipes call for butter to be room temperature. If you substitute shortening or margarine for the butter in the recipe, the results will not be the same. When it comes to using shortening, the resulting texture will be more cake like. If that is what you are going for then by all means mix shortening with the butter or go for all shortening, but it will also affect the taste.
Adding applesauce in place of some of the shortening is one way to add moisture to your cookies. It also reduces the calories, which makes it a popular diet choice.
Among the other ingredients that can affect the softness and moisture in your cookies is the sugar. White sugar has less moisture than brown sugar. There is a taste difference between these two types of sugar, so you have to be aware of that if you are going to be doing substitution. In a chocolate chip or an oatmeal cookie, brown sugar should not affect the flavor too much, but in something like shortbread, the taste of the brown sugar may overwhelm the other flavors.
The amount of time that a cookie spends in the oven will also affect the moisture and softness of the final result. For a moister cookie, under-cook it a bit. Listen to your cookie, they “talk.” You will get used to the sound they make and be able to tell as soon as it stops it is time to take it out of the oven. One you know how long it takes to stop “talking,” take the next batch out a minute or so sooner. They always continue to cook a little after they are removed from the oven.
When you store your cookies, place them in an airtight container with a piece of white bread and they will remain soft and moist for as long as they last.