Normally a chocolate or blueberry muffin is sold for £2.25 in the Balmoral coffee Shop. The queen will also be throwing open the gates of the 50,000 acre Royal Deeside estate to the public for one night only on Sunday May 15.
Spectators will be able to watch the final of the QE90 event staged at Windsor Castle beamed live onto a giant screen in front of the castle.
More than 900 horses, musicians, dancers, actors and artists will be performing in the theatrical spectacular.
But Buckingham Palace has revealed there will be no official public celebrations in Scotland. A spokesman said: “She will be doing Holyrood week, and opening the Scottish Parliament, but that will be the main focus in Scotland.
“Obviously there will be patron’s lunches and events around the official birthday in June, all being well. But those are being driven by communities.” There will be 9,000 guests at the sponsored street party from organisations of which the Queen is patron, with a further 1,000 paying £150-a-head .
The Queen has been cutting down on her official engagements gradually as she and Prince Philip, who is 95 this summer, wind down.
She normally spends around 63 nights a year at Balmoral and is looking to stay longer in the future, it has been reported.