LONDON — Prime Minister David Cameron praised her coolness under pressure. Bookmakers monitored her performance as they do election candidates. Television watchers admired her raspberry mille-feuille and soda-flavored cheesecakes — along with her blue chocolate peacock, and a mountain of éclairs in the form of a nun.

The victory of Nadiya Jamir Hussain, a petite 30-year-old, head-scarf-wearing mother of three from northern England, in a wildly popular reality show called “The Great British Bake Off” on Wednesday has been greeted by many in Britain as a symbol of immigration success, at a moment when the country’s leaders, Mr. Cameron included, have expressed concerns that it has too many newcomers.

Ms. Hussain’s popularity, bolstered by her self-deprecating humor and telling facial expressions, helped the final episodes of the baking program, in which contestants vie with one another to make a variety of desserts, attracting well over 10 million viewers per show, according to news reports. She has also become a darling of social media, with more than 63,000 followers on Twitter as of Thursday afternoon.

In a country where baking stodgy desserts has a history dating back centuries and where the preparation of sweet treats is considered a quintessential part of homespun culture, the success of Ms. Hussain, an observant Muslim, spurred debate about national identity.