Applesauce is a potent "secret weapon" in the arsenal of many bakers. It can be used to add moisture and flavor to a recipe that's already good, such as your favorite muffin or spice cake. It can also serve as a substitute for oil or eggs in many recipes, reducing fat or helping work around a food allergy. Yet its odd, semi-solid texture poses a conundrum for some bakers who don't know whether to measure it in a wet or dry cup.
Wet vs. Dry Cups
The whole question of wet and dry measuring cups is confusing to many bakers, and there's a lot of misinformation on the Internet. The simple truth is that the two measure volume identically, but have practical differences. Dry measuring cups have a level, uninterrupted top edge. That's so you can fill them and then level them by skimming the top with the edge of a knife, getting a more-precise measurement. Measuring cups for liquids have additional space at the top, so you won't spill, and have a pouring spout. There can be tiny variances between manufacturers, but if you fill a dry measuring cup to the brim and pour it into a wet measuring cup you should see the same measurement.
Well made applesauce has a moderately thick and viscous texture, like other fruit or vegetable purees. That means it's unlikely to spill during transport, so it could conveniently be measured in a dry measuring cup. On the other hand, if your applesauce is thin and soupy, you might prefer to use a liquid measuring cup. In either case, the cup should be scraped with a flexible spatula to ensure that all the applesauce goes into your mixing bowl. There aren't any hard and fast rules about which type of cup to use, so it largely comes down to personal preference.
Pros and Cons
Applesauce is a variable ingredient at best because its moisture content is uncertain. However, if you always make it the same way -- or always buy the same brand -- your choice of measuring cup can help you be consistent. Applesauce tends to mound in the cup when it's spooned in, so using a dry measure and level ing to the top of your cup can be a benefit. Alternatively, liquid measuring cups tend to be clear or translucent, so you can see if there are large air bubbles in your applesauce that would affect the measurement.
Using your Applesauce
Unless you're adding just a few tablespoons for moisture, you'll need to adjust your recipe when substituting with applesauce. Although it contains apple solids, it should always be counted among the wet ingredients in your recipe. If you substitute a quarter-cup or more of applesauce, you should reduce the other liquids accordingly. A half-cup of applesauce is the most you should substitute into most recipes without making them dense and chewy. If you're replacing fats or dairy products in a recipe, use half applesauce and half of the original ingredient. If you're replacing eggs, a half-cup -- equivalent to two eggs -- is usually the limit.