MangaDex

Nanchatte Cinderella Oukyuu Inbou Hen Isekai de, Outaishi hi Hajimemashita.

Izumi Maya, a 33-year-old professional pastry chef, who went out to buy some mustard, gets caught in an accident. When she regains consciousness, she has been reincarnated as a 12-year-old princess! On top of that, she also has a husband who is older than her! And a king, no less! Maya realizes that she's in a position where her life might be targeted, thus, decides to try to get along with her husband to protect herself! In the name of a pastry chef, I’ll defeat the criminal and my husband’s stomach at the same time!!