Bangladesh-origin Hussain tasted victory in last year's baking extravaganza, Great Bake Off.
This week she added icing to her illustrious career by bagging the rare honour of baking the birthday cake for the Queen.
Nadiya told the BBC that when she was first offered the task she thought it was a joke.
But when the reality dawned on her, she said she was as nervous as she had been just before pulling off the Bake Off victory last year.
Queen Elizabeth celebrated her 90th birthday at Windsor, walking most of the time, accepting compliments from the crowd.
The Queen joked, “does it cut.” A nervous Nadiya replied she hoped so.
As the Queen cut the cake everyone broke into a rapturous, "Happy Birthday To You".