Stacy De Novo is a young confectioner who owns a sweetshop in Chicago with her collaborator and good friend, Kevin. The latter has a daughter named Olivia, from a marriage that ended prematurely with another woman. A week before Christmas, Stacy discovers that Kevin has enlisted his business in the world’s most important cake competition in the Belgravia Kingdom.
Although hesitant and excited at first, Stacy is convinced to attend and, together with Kevin and Olivia, the three go on their way to Belgravia; there the three meet a person who sells Christmas socks, and this dog looks very familiar to Stacy, not even sure of where. This person urges the girl to live her life with more passion – Stacy being very closed and chaotic after she broke up from her boyfriend Paul.
After arranging the luggage in the beautiful home to live, Stacy and Kevin arrive in the TV studio where the competition will take place, and Stacy meets with Brianna, a former winner of this competition that is determined to do everything in its power ( both good and bad) to secure a new victory and, implicitly, the preservation of the trophy he won a year ago. Differences begin immediately when Brianna sabotages a cake to Stacy, but this event will bring Stacy alongside Lady Margaret of the Montenaro region, Duchess and the future bride of Prince Edward. The two realize with stupor that it looks like physically and the two agree to exchange roles for a few days.