When 7-year-old Tessa Reagan's birthday rolls around each year, she and her mother, Lisa Agoglaiti, head to the local Baskin-Robbins store, where Tessa gets to pick out an ice cream cake. "She's not a kid that likes a regular cake with lots of frosting," says Agoglaiti, of Silver Spring. "She'll just scrape it off."

Ice cream cakes are one of the most popular ways to celebrate birthdays, especially in summer. "Parents are busier these days. And the ice cream cakes are not only easy to pick up and convenient, but they're the novel alternative to a standard sheet cake," says Deborah Benke, publisher of Washington Parent magazine.

Their popularity seems to be growing. At Carvel Corp., one of the nation's leading makers of such cakes, sales are up 8.2 percent in the last year in the 485 supermarkets in the Washington-Baltimore area that carry its products, according to company spokeswoman Jennifer McLaughlin.

The Food section sampled some of the best-selling ice cream cakes made by chain ice cream stores. We asked Jewel Zimmer, pastry chef at the three-star CityZen restaurant in the Mandarin Oriental hotel in downtown Washington, to help us judge them in a blind test.

After cutting into each one, we discovered a few surprises:

Not all ice cream cakes even have cake inside. Some have a layer of cookie crumbs, and others are solid ice cream.

Some cakes are difficult to cut and serve. A Maggie Moo's cake, for example, holds its shape on a hot afternoon better than one from Cold Stone Creamery. But there can be a notable trade-off in flavor.

Our advice: Always call ahead for availability; order 48 hours in advance. Also, prices can vary widely for the same cake at different locations of a franchise store. And keep in mind that ice cream cakes are dense and serve more people than you might expect.