Mango nectar is a noncarbonated beverage made from the pulp of mangoes. Shop for it in the fruit juice aisle.
For a colorful accent, top the cake with fresh lime wedges.
An easy way to grate citrus peel is to use a microplane grater. It was originally a woodworking tool, but it’s now sold for kitchen use. The delicate grated lime peel in this recipe adds a complementary flavor to the cake.