Powerful, heady fortified wines such as Marsala and sherry are a pleasant sipping beverage in their own right, but they're also widely used in cooking and baking. Cream sherry, for example, is a common ingredient in cakes, glazes and prepared desserts such as England's cherished "trifle." If you don't have cream sherry at your disposal, several other sweet, fortified wines can be substituted with good results.
What You're Replacing
Sherries are complex wines traditionally made through a lengthy aging process, although modern industrial versions use a variety of technological tricks to yield a marketable result in a hurry. Cream sherries are very sweet and alcohol-heavy, and they are deliberately oxidized during production to create concentrated, caramel-like flavors. Other dessert wines provide comparable levels of sweetness and alcohol, though cream sherry's distinctive flavor notes are harder to replicate.
Some Substitutions
One strong alternative to cream sherry is tawny port, a similarly potent wine that's also oxidized to create a distinctive flavor and its namesake color. While their flavors are not identical, tawny port works equally well in most recipes. Sicily's famous Marsala, used to make frothy zabaglione, provides a different but equally interesting flavor in most recipes. Marsala is available in many levels of sweetness, with "dolce" providing the best substitute for cream sherry. Madeira, produced on the Portuguese island of the same name, is another viable substitute. In a pinch, sweet vermouth can also be used successfully in many recipes. Its slightly herbal flavor isn't always appropriate, but it lends complexity to some desserts.