Sir Boyd Tunnock said she chose the teacake from the Scottish brand over the caramel wafer, which was created by his father.
Sir Boyd, 86, who runs the family-owned business in Uddingston, South Lanarkshire, received his honour on Thursday for services to business and charity.
Afterwards, he said: “She said she prefers the teacakes and I said I’ll send her some over.”
Sir Boyd created the Tunnock’s teacake – marshmallow on a biscuit base coated in chocolate – in 1956.
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The caramel wafer, made up of five layers of wafer, four layers of caramel and fully coated in chocolate, was created by Sir Boyd’s father Archie in 1952.
Sir Boyd joked: “I prefer the caramel wafers but only because we make more money from them.”
Describing the investiture ceremony, Sir Boyd said it was “excellent” and “awesome” to receive his honour from the Queen.
“It was very regal,” he said. “The music was great, I was standing there swaying and I could have danced all night.
“The Queen is so nice and makes you feel very relaxed.”