Prince William and wife Kate Middleton pose with Mary Berry after baking one of her recipes — a Christmas meringue roulade.

They then compared their creations with Bake Off star Nadiya Hussain in Rosewood London hotel’s winter chalet.

William, 37, was filming “A Berry Royal Christmas” for BBC1 in which he visits charities with Mary, 84.

Speaking to Mary, 84, at homeless charity The Passage, which he first visited with his mother Diana, Princess of Wales aged 11, he said: “Growing up, both of my parents were hugely charitable.

“My father set up the Prince’s Trust. He’s involved in so many different organizations.

“My mother has done her work with homelessness and as you said AIDS and other charities and I think I’ve grown up in a household which has been very much a case of ‘well, we’re very lucky – you must give back.’

“And you know, my grandmother becoming Queen at a very young age, in the days when it was a man’s world, it was very difficult for her to … make a difference. And she’s done it.

“In her own very unique, distinct way, and you know, my grandmother and my grandfather together are the epitome of public service.

“And I personally get a lot out of helping people.

“I find that you hear and you understand and you learn so much more by giving a bit of your time, a bit of your day, to just be around.”

They also held a party to thank and acknowledge staff from the charities.

Their visit to The Passage – which is the UK’s largest resource center for homeless and insecurely housed people – cemented William’s life-long connection to the charity, which he visited with his mother in 1993.

Established in 1980, it has helped over 130,000 people in crisis through its resource centre, homelessness prevention projects and two innovative accommodation services.

Mary will also join The Duchess of Cambridge behind the scenes at RHS Wisley where she will have a tour of Wisley’s new play garden – inspired by the ‘Back to Nature’ garden that she co-designed at the Chelsea Flower Show.

“A Berry Royal Christmas” will air on December 16, at 8.30pm on BBC1.