"Who's afraid of middle school? Not Katie Brown. After all, it can't be that different from elementary school. But, boy, was she ever wrong! After her best friend ditches her for a new group of friends called the Popular Girls Club, Katie is left alone and starts to wonder if there's an Unpopular Girls Club she can join. Luckily, Katie finds her way with a great new group of friends and together they form their own club. Four friends plus cupcakes...

Alexis Becker loves to organize and plan and set goals, which is why she is in charge of the business end of the Cupcake Club. But when she suddenly develops a major crush on Matt Taylor - who happens to be Emma's brother - things get a little disorganized

Mia tries to make friends with Olivia, the new girl, but when Olivia makes fun of the other Cupcake Club girls and tells Mia she shouldn't hang out with them, Mia must make a decision about her new friendship

Katie starts to realize that doing what you love always makes the batter sweeter

When Alexis decides she wants to be more like her popular older sister, Dylan, she tries out for cheerleading, without really thinking about what that entails, including that her sister was a star on her cheerleading squad.

Reaching a compromise with her parents when they say she is too young to attend a concert alone, Mia discovers that she is being cyberbullied on social media and teams up with her fellow Cupcake Club members to discover who is behind the attacks.

Emma's younger brother Jake has tonsillitis and makes life difficult for Emma, while the Cupcake Club girls are spoiling him with cupcakes and little gifts

When Sydney moves away and is replaced by newcomer Olivia, Alexis becomes the focus of hurtful teasing by the Best Friends Club and begins to wonder if an offhand remark she made when first meeting Olivia may have been taken the wrong way

"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!"--

When Katie learns her mother's new boyfriend is her math teacher, Mr. Green, Katie is accused of getting special treatment in class, and it's the Cupcake Club to the rescue to help Katie deal with the rumors and the changes in her life