Once the darling of bake sales and birthday parties, cupcakes are no longer child's play.

The standard cake-mix-and-canned-frosting variety we loved as kids still have their place, but newer, more sophisticated, and certainly more expensive models have moved in.

Today's beauties are crowned with miles of elegant icing, filled with fruit or cream, and intricately decorated like mini-masterpieces.

The simple miniature cake has morphed not only in trendiness, but in size, like its sibling, the muffin.

Magnolia Cafe and a few other New York bakeries launched the trend a few years ago, when they started selling nothing but the beautifully frosted creations.

Soon, tiers of elaborately decorated cupcakes began replacing wedding cakes.

Why the surge of popularity for the once-humble treat?

Cupcakes are fun, inviting, casual. They are portion-controlled - creating equity for siblings and encouraging restraint on the part of dieters.

They're versatile, offering tons of decorative styles, and are easier to bake and ice than traditional layer cakes. And easier to eat. (No knife, no fork, no plate!)

Anne Byrn, author of "Cupcakes! From the Cake Mix Doctor" (Workman Publishing, $13.95), thinks it's more than just the size and styling that explains their success. Cupcakes, she said, feed our nostalgia.

"They're a taste of your past," Byrn said.