The Big Mistake You're Making With Store-Bought Sugar Cookie Mix
Before we dive into this topic, we'd like to assure you that we're not going to say that it's a mistake to use a prepackaged mix in the first place. Store-bought sugar cookie mix is great stuff and such a time-saver! If you want to get fancy, there are various hacks you can use to make it taste more homemade such as mixing in nuts, chocolate chips, or dried fruits or altering the flavor just a bit with almond or lemon extract. Even if you stick to following the recipe exactly as given on the package, though, you'll still have a choice to make: butter or margarine. We'd say go with the former if you can.
There are valid reasons to use margarine in baking, such as the fact that it may be plant-based and does tend to be significantly cheaper. If neither of these is a concern, then we would say that butter is a better bet. Not only does this ingredient taste more, well, buttery (duh), but the fact that it contains solidified milk fat rather than the oil that margarine's made of leads to cookies that bake up softer and fatter instead of spreading out all over the pan.
Salted or unsalted?
While some sources may warn that using salted butter in your sugar cookies will lead to them tasting excessively salty, this may be unnecessarily alarmist. Salted butter typically only contains about ¼ teaspoon per stick, which is the amount of butter called for in a 17.5-ounce bag of Betty Crocker sugar cookie mix. Chances are, if you typically use salted butter in baking, you won't notice any excess salt in your cookies. In fact, you may even find the cookies slightly bland if you switch to the unsalted kind. If, on the other hand, you're already baking with unsalted butter on a regular basis, well, you'll likely have the stuff on hand, so go ahead and use it. It's strictly a matter of personal preference here, as the salt won't affect the cookies to any great extent.
Of course, there's one reason besides flavor why you might choose to go with unsalted butter, and that's because it's sodium-free. Salted butter, on the other hand, may have 720 milligrams per stick (though it varies by brand). The Food and Drug Administration recommends keeping your daily intake under 2,300 milligrams. Of course, each cookie will only contain a fraction of that — 33 milligrams if you're using the Betty Crocker mix, plus another 65 milligrams from the mix itself for a total of 98. That's about 4% of the recommended maximum amount of sodium, but using unsalted butter would result in a cookie with just 3% so plan accordingly.