Kate Middleton and Prince William's Wedding Cake Baker Reveals Awkward Moment with the Queen

Kate Middleton and Prince William's extraordinary wedding cake required some tricky maneuvering at Buckingham Palace.

Fiona Cairns, who led the team behind the royal couple's wedding cake in 2011, appeared on ITV's new documentary The Day Will and Kate Got Married to discuss the behind-the-scenes difficulties to get the eight-tiered, three feet-tall fruit cake design into the reception venue — which just happened to be Queen Elizabeth's royal residence in London.

To bring the cake inside to the Picture Gallery in Buckingham Palace, the team had to remove a door. And when the Queen came to visit the team as they were putting the finishing touches on the dessert, she made an unexpected remark about the struggle.

"I can remember her saying, 'I hear that you've been dismantling my house,' " Cairns said in the documentary. "And I said to her, 'Well, we had to take a door down from the room below for the trolley to go through with the cake.' But it was all put back so in the end, it was fine."

RELATED: The Most Glamorous Royal Wedding Cakes Through History

Lewis Whyld/WPA Pool/ Getty; Pascal Le Segretain/Getty

John Stillwell/PA Images via Getty Fiona Cairns

The traditional fruitcake was adorned with 900 leaf and floral touches and topped with the couple's cipher.

The enormous cake lasted beyond the wedding reception — in fact, pieces of the fruitcake were served at all three of William and Kate's children's christenings, most recently for Prince Louis in 2018.

Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!

John Stillwell/PA Images via Getty Kate Middleton and Prince William's wedding cake

John Stillwell/PA Images via Getty Kate Middleton and Prince William's wedding cake

RELATED: PEOPLE Celebrates Kate Middleton and Prince William's 10th Anniversary with Special Edition

The wedding at Westminster Abbey was followed by two Buckingham Palace receptions — the first, hosted by the Queen for 650 guests, and a second gathering for 300 hosted by the groom's father, Prince Charles — where the duo mingled freely while always keeping a watchful eye on the other.

Ian Gavan/GP/Getty Prince William and Kate Middleton with their bridemaids

Get the premiere issue of PEOPLE Royals for glamorous new photos and inside stories royals fans haven't seen or read elsewhere! Subscribe at peopleroyals.com/launch

"They're definitely a team," observed Christopher Warren-Green, the music director of the London Chamber Orchestra, which played at the wedding. "They ask each other, 'Should we do so-and-so?' You can just see it."

Kate, 39, and Prince William, 38, are celebrating their tenth wedding anniversary later this month, on April 29.