The Curse of the Chocolate Phoenix, by Kate Saunders (Delacorte, Dec. 2016), brings back twins Oz and Lily, and their friend Caydon, for another adventure involving magical chocolate (Oz and Lily's family have a somewhat dubious heritage of mixing of magic with chocolate, as explained in The Whizz Pop Chocolate Shop). Although this is a sequel, it stands alone just fine, and it's a fun "magical romp" (meaning mostly lighthearted adventure with magic) with some evil antagonists, a talking cat, a young vampire (though she's been 11 for several centuries) and time travel.
It starts when the talking cat finds some crumbs from the chocolate phoenix imbued by the twins' Uncle Isadore with time travel magic. Her visit with Queen Elizabeth has no great implications for the stability of the time stream, but the magical enforcement agency of London is worried. With good reason--sinister forces are at work, determined to use the time travel chocolate to change the course of history (for the worse). Silver, who was made a vampire when she was 11, several centuries ago, is assigned to the kids to be their bodyguard, because they have the right magical heritage that enables the chocolate to work its magic.
And because of this, they are sent on two missions to make sure the past happens as it should--the first, to make sure the Great Fire of London happens, and the second, to make sure that St. Paul's isn't burned in WW II. Both are exciting time travel adventures, although the actual experience of being in the past is not the point; thwarting the villains, with good reason, absorbs the energies of all concerned.
Even though there are plenty of tense moments, when Lily in particular is not as brave as one would like ones young fantasy heroines to be (though goodness knows I two would be a mess if I was thrown into the prison of child-eating giants to be their next snack), the whole ensemble is good magical adventure fun. The magical world is broadened somewhat in this second book in the series, and there's lots of potential for more character growth and world building to come!
The true hero is the immortal talking rat, Spike; the kids themselves are mostly pawns in the battle of grown-ups. But it's plenty diverting to just go along with them for the ride!
Caydon's family is from Jamaica, providing some diversity (and I think it's cool that he got to be front and center on the phoenix); I hope we see more of his grandma in future books!