The Cupcake Club comes to Katie’s defense when a surprise at school leads to unfair gossip. When Katie’s mom says it’s time for Katie to meet her new boyfriend, Katie is excited and nervous. She thinks she’s prepared, but she’s shocked instead. Her mom’s boyfriend is Jeff Green—as in Mr. Green, a math teacher in her grade! Katie tries to act as normal as possible, but when mean girl Olivia finds out, she tells everyone that Katie is getting special treatment because her mom is dating a teacher. How can Katie stop Olivia and deal with all the new events in her life? It’s the Cupcake Club to the rescue, as Katie’s friends come to her defense, including an unexpected ally.

Katie is about to burst when the rest of the Cupcake Club entrusts her with their secrets, but this group of best friends soon realizes that sharing and keeping secrets is what friends are for.

The girls realize that it is great to have friends and they are a lot like cupcakes you can't have enough and they are good in all combinations.

Katie is unpleasantly surprised to find out her family is moving into a new house after her mom’s wedding in the latest addition to the Cupcake Diaries series. Katie’s mom is getting married! Katie and her three best friends couldn’t be happier and have so much fun pitching in with getting ready for the big day—especially with cake testing! But when Katie finds out her mom’s marriage means her family has to move, suddenly the wedding isn’t as joyous an occasion. What will life be like in a new home with a new family?

Can the new Fashion Club be the icing on the cupcake for Mia, or is she in over her headshot? When fashionista Mia hears someone is starting a Fashion Club at school, how can she resist? But can she manage to take part in two clubs at the same time? And what will her Cupcake Club friends think about this? Worst of all, Mia’s frenemy Olivia Allen wants to be in charge of the Fashion Club. Can Mia and Olivia make peace long enough to survive a fashion show?

Mia goes on vacation and meets up with the girls from the Sprinkle Sundays series in the latest addition to the Cupcake Diaries series! Things are slow at the cupcake shop this summer, and so when Mia’s dad invites her on a long weekend trip to meet some of his college friends, she jumps at the chance—especially when she hears they have daughters her age. It turns out the girls work in an ice cream shop. Not only does Mia end up making new friends—she comes back with a new invention for the Cupcake Girls: an ice-cream cone cupcake!

Katie has a tough time keeping one secret…what happens when she has to keep four? All of the cupcake girls have secrets and are ready to burst! Katie loves knowing a secret; it's just tough for her to keep them! And in this story all her friends have told her a secret! From new crushes to someone cheating on a math test, Katie doesn’t know what to do with all of this juicy information! Can the Cupcake Club survive with everyone keeping secrets from one another? The girls soon realize they need to confide in each other—after all what are best friends for if not for keeping your secrets?