The Delectable Tart by Merry Farmer

A ruined reputation is a sweet entry into sin…
Life is decidedly unfair for Miss Sophie Barnes. After her sisters’ falls from grace, she has been left without friends, without a place in society, and without the first clue what to do with her life. All respectable paths are closed to her, but she still wants to make a name for herself instead of feeling invisible in her own skin. And as it turns out, being seen in nothing but her skin might be the solution she’s been looking for.
Jonathan Foster is the illegitimate son of a sugar plantation owner, and though running his father’s business in London has made him wealthy, his true calling is as a pastry chef and confectioner. When he meets Sophie, he sees her as the perfect canvas for his art and the perfect companion for his life. Ambition has never tasted so good.
But when a familiar villain is discovered to be selling secrets to French pirates, Sophie and Jonathan must stretch their delicious new alliance to do more than just entertain the members of the ton who once turned their backs on Sophie, they must catch the spies and see them brought to justice.