Didi Dodo Future Spy: Recipe for Disaster by Tom Angleberger

His Super Secret Fudge Sauce ingredient and recipe are missing.  When he's called the cops and is despairing over having his cookies done in time for competition, in comes Didi Dodo on roller skates.  After flipping over the front counter and landing in the cookie dough, she tells him she's come to save him and find his recipe!

Amulet Books sent me a copy of this book to read for review (thank you).  It is being published today.

Koko can't tell her what the secret ingredient is because he doesn't know.  It was part of the recipe that is missing.  But Didi isn't discouraged.  She has resources she can use to identify the smell and get the content defined and she's going to the competition to see who else wins the contest because they would most likely be the thief.  

Get ready for lots of hairy action and messes everywhere.  Traveling by roller skates is dangerous.  So is the mall cop.  But it makes for a fun story...