Having won the celebrity Great Sport Relief Bake Off earlier this year, the singer was delighted to devise a poppy-themed cake as part of HELLO! magazine's partnership with The Royal British Legion.
The special cupcakes – with the Legion's bright red flower emblem proudly emblazoned on top – were carefully crafted by Geri ahead of the Patron's Lunch on 12 June, the highlight of the Queen's milestone birthday festivities.
The lunch will see 10,000 people enjoying a huge street picnic on The Mall in the shadow of Buckingham Palace, with HM The Queen as guest of honour. Those without tickets are encouraged to host their own Royal British lunches and street parties, and these cupcakes, which also feature a golden crown on top, would be the perfect treat to serve.
Geri, 43, who earlier this month celebrated her first wedding anniversary to Formula One boss Christian Horner, was thrilled to be back in the kitchen for such a worthy cause. She was equally delighted to let Second World War veteran Danny McCrudden, 91, sample the first batch of the cakes.
She told HELLO!: "I think the Queen is absolutely amazing and an inspirational person for so many reasons. She has maintained such dignity and grace throughout her reign. I think she has been a wonderful figurehead for our country.
"I am absolutely thrilled to have been asked to make these cakes," Geri added. "When I meet people who have lived like Danny you just think 'wow' about the things he has experienced and seen and done. They all deserve to be treated with an incredible manner of respect and he has learnt a lot that he can share with us. I think the older generation deserve lots of respect."
Danny who lives near Dagenham but is originally from Glasgow, joined the Royal Navy in 1943 and served until 1953.
And his verdict on Geri’s cakes? "Quite delicious and a very fitting way to celebrate such a momentous occasion," he said.
Geri, who helped launch the Poppy Appeal with the Spice Girls in 1997, said she is also a huge fan of The Royal British Legion, which produces millions of Remembrance poppies each year to raise funds for its work with the Armed Forces community.
"I think it is really nice that the Legion supports people in the way they do. Danny has given so much of his life to Britain and it was so great to meet him. I think it's incredibly important to show these brave and courageous heroes a tremendous amount of respect; it was an honour to be in his company today. I had a great time.
"I'm always keen to show my support to the Queen, too. Sometimes when I’m pondering on a decision, I ask myself... what would the Queen do..."
The Royal British Legion is encouraging communities to hold their own Royal British Lunch to celebrate the Queen’s long patronage of the charity and we’ve produced a special pack to help organise your event. Find out more and register your event here.