There are many reasons why cupcakes can result dry, but the two main ones are: 1) Overbaking: the cupcakes have stayed in the oven too long and too much moisture has been removed from them. This can happen the first time we try a recipe, especially if we have a new oven or we are using one we are not familiar with; try adjusting the cooking time next time you bake them. 2) Too much flour: the dry ingredients such as flour or cocoa powder have been mismeasured and too much has been added, making the batter thicker than needed and the result drier. When making desserts, although using a measuring cup most of the time carries a good result, using a scale with grams or ounces is much more precise and a good choice if available; it is easy to add too much flour mixture when using cups and also just one extra tablespoon can make a big difference if paired with one extra minute in the oven.