“The Great Holiday Baking Show,” based on the hit UK series, “The Great British Bake Off,” is hosted by Nia Vardalos (“My Big Fat Greek Wedding”) and husband Ian Gomez (“Cougar Town”). “The Great Holiday Baking Show” stars some of the nation’s best amateur bakers as they compete in a series of themed challenges and eliminations all hoping to be crowned Holiday Baking Champion. For four weeks, James Beard Award-Winning pastry chef and author, Johnny Iuzzini, joins England’s “Royal Queen of Baking,” author and television personality Mary Berry, as they judge the decadent and delicious holiday fare these bakers create as they throw down their best culinary skills.