Mrs. Amster, a home economics teacher, and Mr. Barish, a history teacher, interrupt Mrs. Mondt's class to announce The Ultimate Outrageous Cake Competition, where students enter history-themed cakes. Reception is lukewarm until Mr. Barish mentions that the winner will receive extra credit in both of their classes by half a grade, catching the attention of the Biskit Twins. After class ends, Blythe chooses to also enter when Youngmee lends her support, as she helps out at a sweets shop. The Biskit Twins overhear this and discuss among themselves if they should enter. Brittany suggests entering to see Blythe lose, and Whittany obliges, having thought up a nasty scheme.
At Sweet Delights, Blythe, Youngmee, Sue, and Jasper discuss what to theme the cake on, and they decide upon the Taj Mahal. The four of them split up to work on different tasks: Sue will do the research, Jasper will gather materials, Blythe will look for pictures for accuracy, and Youngmee will create the cake.
Buttercream, who has overheard the discussion, returns to The Littlest Pet Shop and fills the other pets in on what she remembers. Unfortunately, Buttercream remembered it all wrong, and Vinnie interprets her words as cake taking over the world by filling up hallways, working himself up into a worry. At the same time, Buttercream demonstrates her newest game, Butterscotch, which Sunil, Zoe, and Russell gladly partake in. Vinnie sees Blythe run through the store front in a panic yelling "Cake!" repeatedly, however, and becomes terrified. Blythe prints out her image of the Taj Mahal and runs back out.
At the Biskits' mansion, the twins' scheme turns out to simply be to make their butler bake the cake for them. Their father Fisher catches them trying this and forces them to do it on their own, then leaves with their butler. The Biskit Twins acknowledge that they can't make a decent cake, but Whittany decides to sabotage Blythe's team so they win by default. They follow her to Sweet Delights under the guise of reporters. Blythe and the others see through it right away, but the Biskit Twins manage to steal their recipe and cake design anyway. Buttercream witnesses it and tries to tell Blythe, but Blythe is too preoccupied with her duties to notice Buttercream.
Buttercream rushes to The Littlest Pet Shop. She says that Blythe is heading for a cake-related emergency, upon which Vinnie grows even more alarmed. When Russell hears Roger telling Mrs. Twombly he's heading for the school to see the cake competition himself, Russell and Zoe accompany Buttercream into Roger's car. Vinnie, who has now donned cowboy attire, follows along to make sure he stops the cakes.
Four teams have entered: Blythe's team, the Biskit Twins, a trio of jocks, and a trio of goths. Each member of Blythe's team came thinking someone else had the recipe card and cake design, but they soon realize it's gone. Blythe attempts to get extra time to find their missing information, but Mr. Barish begins the competition right away. Buttercream shows Russell and Zoe that the Biskit Twins stole the cards, and they sneak over to try to get them back. Buttercream, filled with rage, leaps onto the stage and sneaks her way to the Biskit Twins' table. Knowing Buttercream is in danger, Russell, Vinnie, and Zoe get onto the rafters and drop eggs and cinnamon onto Whittany's head until Mr. Barish climbs up there to investigate. The pets swing back down onto the ground but have bought Buttercream enough time to spot the recipe card and cake design. She brings the cake design back to Blythe but unknowingly drops the recipe card, which stuck itself to one of the jocks' shoes. Youngmee tries to recall as much of the recipe as she can from memory, and they proceed.
After all the cakes have finished, Mrs. Amster and Mr. Barish start judging on appearance and taste. The Taj Mahal cake outdoes the goths' Eiffel Tower cake and the jocks' Alamo cake by a landslide. The teachers then turn to the Biskit Twins, who have made a freaky-looking cake sculpture of themselves. The heads on the cake soon fall off, spraying red borscht berry everywhere like blood and inducing screams and panic on everyone who watches. The teachers declare Team Youngmee the winners, Fisher gets his daughters home glad that they tried, and everyone calls it a day—except for Vinnie, who sees the cake as one of the villainous pastries he feared about. He smashes the Whittany head and brings the Brittany head back to The Littlest Pet Shop as a victory trophy as Blythe hands Russell, Buttercream, and Zoe slices of their cake as a reward for their help.
This episode contains examples of (YMMV entries go here):
- Absentee Actor: Pepper and Penny do not appear in this episode whatsoever, meaning Tabitha St. Germain and Jocelyne Loewen sat this one out.
- Brick Joke: Jasper turns down Sue's Gertrude Ederle suggestion because they're not making a soup. Much later, the Biskit Twins make borscht soup for the cake competition.
- Call-Back: The Biskit Twins once again attempt to sabotage Blythe, whom they see as tough competition. They seem to have become slightly better at disguising themselves too, but just slightly. From the same episode, we also had Russell's previous time climbing onto a stage's rafters to disrupt the Biskit Twins.
- Calvinball: Butterscotch. Vinnie does a correct sequence of hops, letting Zoe win (who has done absolutely nothing at all).
- Comically Missing the Point: When Buttercream retrieves the Taj Mahal design to Blythe, Blythe wonders where Buttercream came from. Buttercream proceeds to describe her birth.
- Another case not a minute afterwards:Whittany: Brittany, tell me you found Blythe's recipe card.Brittany: Like, okay, I found Blythe's recipe card.Whittany: You did!?Brittany: No, but you told me to tell you that.
- Another case not a minute afterwards:
- Conspicuous Trenchcoat: The Biskit Twins in Sweet Delights.
- Continuity Nod: The Biskit Twins continue to express their disdain for math at Mrs. Mondt.
- Blythe can do a pretty good impression of the Biskit Twins. Makes sense considering she once almost assimilated herself among them. Their garçon returns too and is now given the name of Monsieur LeGrande.
- The Biskit Twins insist on vanilla imported from France or Spain, paralleling Christie's insistence on vanilla from Madagascar in "Topped with Buttercream."
- Most of the members of the other teams have been seen in many prior episodes in the background.
- This marks the third time the Biskit Twins get food on their heads, after "Blythe's Big Adventure Part 2" and "What's in the Batter?"
- Vinnie gets to smash pastries again.
- Gossip Evolution: Blythe and her friends are making a cake themed on the Taj Mahal, which they believe is one of the Seven Wonders of the (Ancient) World. Buttercream recites it as cake filling their hallways so people from seven worlds can wonder. Vinnie then hears it as cake taking over the world by filling up hallways people wander through.
- Hidden Depths: A subtle one here—Vinnie is shown to enjoy eating the Biskit Twins' cake, meaning they can make one that tastes at least passable in spite of their complete lack of confidence in their baking skills.
- High Pressure Borscht: The Biskit Twins' cake's necks spew out red filling like it was a Mortal Kombat game.
- Incredibly Lame Pun: Roger shouts, "Blythe! What's cooking?" to Fisher as he enters the gymnasium. Fisher looks visibly annoyed.
- Just for Pun: The Biskit Twins become interested in binomials because they think the word "buy" is in its name. They then interpret the "historical" cake event as "hysterical." Also:Buttercream: Time to put the "pet" into this com-pet-ition!
- Like Is, Like, a Comma: The Biskit Twins can't help themselves, even, like, when in disguise.
- Ludicrous Gibs: The results of Vinnie stomping on the head.
- No Peripheral Vision: No one in the audience seems to have noticed animals doing stunts onstage.
- Not Now, Kiddo: Buttercream saw everything happen between the Taj Mahal team and the Biskit Twins, but Blythe, the only one able to do something about it, is too busy to notice Buttercream, let alone listen.
- Ooh, Me Accent's Slipping: In-universe. Brittany accidentally slips into her natural voice when undercover, whom Whittany must correct. It happens to Whittany too, though she corrects herself.
- Paper-Thin Disguise: The Biskit Twins as reporters. They fool no one, not even Buttercream.
- Portmanteau: Butterscotch, in addition to being a hard candy, combines "Buttercream" and "hopscotch."
- Reasonable Authority Figure: Fisher insists that his daughters attempt to win on their own efforts. When they lose, Fisher is still happy to see they tried, even if he screamed for about 10 seconds straight upon seeing their cake.
- Seven Wonders of the World: Subverted. The Taj Mahal is not one of them.
- "Shaggy Dog" Story: The B-story of Vinnie's cake paranoia either goes nowhere or resolves by itself, depending on how one interprets the final shot.
- Shout-Out: The hallways in Vinnie's Imagine Spot resemble those seen in The Shining.
- Buttercream calls Vinnie as "Vinnie Vici Vinnie" at one point, referring to Julius Caesar's famous phrase, "Veni, vidi, vici" (also known as "I came, I saw, I conquered").
- The Biskits' butler's name of LeGrande may be named after Gustave Le Grand from the My Little Pony: Friendship Is Magic episode "MMMystery on the Friendship Express," who was also baking desserts.
- The final shot depicts Vinnie licking cream off his face in the very same way Scooby-Doo does in the final shot of the opening for Scooby-Doo, Where Are You!?
- Shown Their Work: Sue's statement about Gertrude Ederle as the first woman to swim the English Channel in 1926 is is correct. In contrast, the Taj Mahal is not one of the Seven Wonders of the Ancient World. It is, however, one of the landmarks chosen in 2007 for New 7 Wonders of the World, which makes Blythe and Youngmee technically correct, as they refer to it as one of the "Seven Wonders of the World" with no further specification on which list they're using.
- Sickeningly Sweethearts: Mrs. Amster and Mr. Barish walk into the classroom giggling and telling sweet nothings to each other. They continue to exchange such lines as they make their announcement in the Cold Open. Blythe and the Biskit Twins agree (for once) that their behavior is screwed up.
- Uncanny Valley: Intentionally invoked with the Biskit Twins' cake, even in the art style of the show.
- Walk This Way: Buttercream's bouncing seems occasionally contagious among the pets. It may be a Butterscotch rule.