It depends on the sugar. There are various types of brown sugar, with different levels of coarseness and colors that range form pale beige to deep dark brown - the darker the color of the sugar, the richer its flavor will be. Demerara has a crunchy texture and is good for making chutneys, for grilling as a topping on creme brulee and for glazing baked ham. It should not be used when a quick-melting sugar is needed, or for jellies, as it will make them cloudy; for these, use white sugar instead.
Light and dark brown sugars can be used in fruit cakes and other moist cakes, some biscuits, fudge and chocolate icings, toffee and fudge, chutneys and some sauces (barbecue, sweet and sour, chocolate and so on). As these sugars are moist they should not be used in light cakes which need creaming or whisking, or in light icings where the additional flavor and color would not be desirable.
Black or very dark brown sugar (also called Barbados sugar) contains molasses; the darker the color is, the more molasses and therefore the stronger the flavor. It is used in the same way as light and dark brown sugars and is perfect for Christmas cakes and puddings, but take care it does not mask delicate flavors.
** Asian Cooking