There are a few things you can count on when you watch Kids Baking Championship: adorable contestants, surprisingly grown-up desserts and, inevitably, some tears. Usually it's the kids who cry, but during the third season, Duff gets emotional too. "They were just baking their hearts out. I couldn't help it," he says. It's easy to understand why he and co-host Valerie Bertinelli become so attached to their pintsize proteges: The two stars not only host the show, but they also serve as mentors and judges, spending up to six hours a day critiquing, consoling and, yes, even crying with the contestants. "These kids have such backbone," says Duff. "If you were to critique my food the way we do theirs, I'd be like, 'You're wrong!'" Valerie agrees: "I could never be as poised as they are." Take a look behind the scenes.

"A few times I've begged our producer to let me help someone and she always tells me no," Valerie says. The only time the hosts can step in is when a contestant is clearly losing it, but even then, they can just offer encouragement, not instruction. Duff tries his hardest to be helpful, though. In previous seasons, he has snuck in pointers on how to use the fondant sheeter and level a cake.

"They've studied previous seasons of the show, they read, they watch videos on YouTube — they know stuff I didn't even learn in pastry school!" Duff says. Some impressive moves: working with isomalt (a sugar substitute) to create sugar art, and using Versawhip (a favorite among cutting-edge chefs) to make foam.

The show is filmed for about a month during the summer at the same studio where adult baking competitions are shot, and nothing is scaled down. The baking stations, equipment and pantry are all standard size. The only concession for kid contestants: They can stand on crates if they’re too short to reach the counter.