This syrupy, low-glycemic natural sweetener comes from the Mexican agave plant. To cook with it, substitute 2/3 cup of agave nectar for 1 cup sugar. Reduce other liquids in the recipe by 1 ounce per 2/3 cup agave nectar; decrease oven temperature by 25 degrees; and increase cooking time by 6 percent. At grocery stores, you’ll find agave nectar in three forms: Amber, which has a dark color and rich maple flavor; light, which is translucent, with a mild and neutral taste; and raw, which is also clear and mild but processed at a lower temperature so it contains more enzymes.