Youngmee bursts into The Littlest Pet Shop to inform Blythe that she and her Aunt Christie have moved their business, a desserts shop named Sweet Delights, next door. The two step outside to see the building getting renovated, where Youngmee's aunt Christie gives the girls test samples of her cake pops. They give their approval, and Christi asks Blythe if their pet rabbit Buttercream Sunday is giving the other pets any trouble.
At The Littlest Pet Shop, Buttercream instanty fits in with the other pets and has a breakdance session with them, and Russell officially inducts her into their ranks. After an introduction to what is available at Sweet Delights and the renovation team calls it a day, Buttercream brings them there through a hole in the wall connecting the interiors in spite of Russell's protests. Initially in awe of the edibles immediately available, Penny spots a painting of a candy landscape on the back wall and, stating she wants to live there, asks Buttercream if they make things like that in the store. Buttercream answers in the affirmative and shows the pets the kitchen, but before she can do anything else, they whisk her inside and start gorging on the raw materials, dropping her signature peppermint candy from her head to the floor near the entrance hole. Before long, the pets have fallen ill, and Penny starts hallucinating. Pepper's stench snaps her out of it though, and she suggests they return to the pet shop. Russell tries to open the door to the kitchen, but it refuses to open.
Blythe brings Youngmee to go to The Littlest Pet Shop, only for the both of them to discover the pets are nowhere in sight. Blythe searches around the day camp room in case they're playing hide-and-seek but soon realizes they're not in the room. Jasper and Sue drop in and join the search, but to no avail. Things go From Bad to Worse for Blythe as Mrs. Twombly returns too, but Blythe successfully holds her off for long enough to discover Buttercream's candy peering through a hole in the wall, deducing that the pets are in Sweet Delights. She calls for them but doesn't receive an answer. Blythe asks Youngmee if they can enter the store, but Youngmee regrets she doesn't have the keys yet. Youngmee borrows Blythe's scooter to find Christie, who has the keys, at her pilates session, but by the time Youngmee arrives, Christie had already left for a manicure. She goes to the nails salon but is told Christie has headed for a watch repair shop. At the pet shop, Blythe grows increasingly anxious as the pets' owners will return any moment.
Back at the kitchen, the pets, all hyped on sugar, have formed a crude social structure resembling a tribe. Russell declares himself the leader, but Zoe and Pepper prove their superior strength and oust him. As Russell and Sunil join forces to fight them, Penny usurps the role of chief and brings Buttercream with her. Russell, Sunil, and Pepper ally to bring Penny and Buttercream down, and soon, Zoe and Minka join in the fray. Vinnie, who has expended his energy running around the kitchen, snaps out of his sugar high and is horrified to see all of his friends fighting among each other. He pleads with them to stop fighting, and one by one, they also release themselves from their sugar-fueled behavior and make peace with each other, remembering that they're friends. Buttercream believes that their actions are a ploy to get Penny to come down, but Penny steps down anyway to Buttercream's surprise.
Youngmee eventually finds Christie outside of an ice cream parlor. After much rummaging, Christie finds the keys, and Youngmee returns to The Littlest Pet Shop to bring the good news to Blythe, Sue, and Jasper. They rush to Sweet Delights, and Blythe sees a lot of frosting smeared against a pair of glass doors. She opens it, and the pets leap out of the room, overjoyed to see Blythe. Blythe and her friends clean up the pets and the kitchen, and Minka recounts what had transpired. After she's done, Blythe offers cake pops, but the other pets scramble off. Blythe, not as sick of desserts as the pets, keeps them for herself.
This episode contains examples of (YMMV entries go here):
- Call-Back: Christie from "Blythe's Big Adventure Part 1" is back and apparently kept her interest in that area of Downtown City.
- Someone stalls Mrs. Twombly from discovering missing pets in the day camp room. This time, it's Blythe.
- Continuity Nod: The pets get trapped inside something again. Blythe even checks in the dumbwaiter to make sure another such incident didn't happen.
- Chekhov's Gun: The peppermint candy. In a way, the smeared frosting on the glass kitchen doors over the course of the episode as well.
- Disney Acid Sequence: "The Sweet Shop" is set in a fantasy candy world.
- Divide and Conquer: Penny becomes the new chief by staying out of the infighting, then moving in when they're all totally distracted and weakened.
- Dumbass Has a Point: Vinnie is usually The Ditz, but he's the first one to realize that the excess sugar is making the pets go crazy.
- Finishing Each Other's Sentences: Taken to an extreme when Blythe and her friends each say one word of a four-word sentence to Mrs. Twombly as they run out the door.
- Foreshadowing: Vinnie mentions a giant gumball machine in "The Sweet Shop Song." When he gets into Sweet Delights, the gumball machine is the first thing that catches his attention.
- Funny Background Event: During "The Sweet Shop Song," Penny and Minka attempt to do some coordinated bouncing on gelatin. Minka bounces to the music, but Penny gets stuck in the gelatin instead.
- Furry Reminder: Zoe and Pepper excitedly lick Blythe's face when they're freed from the kitchen.
- Gilligan Cut: Sue's reassurance to Blythe that they'll find the pets cuts to a panicked Sue screaming, "WE CAN'T FIND THEM!"
- Hammerspace: Christie keeps a lot of baking tools in her handbag, including several mixing bowls, open tubes of frosting despite everything else being completely clean, a blender, and an industrial mixer. When she goes through it in Act 3, there's a pile at her feet large enough to fill up her station wagon's trunk.
- I Can't Believe It's Not Heroin!: Overdosing on sugar causes Penny to hallucinate. Even greater amounts causes aggression and hostility among the pets.
- Idiosyncratic Wipes: Buttercream's hair decoration grows and spins to cover the whole screen, and then the white parts give way to begin "The Sweet Shop Song."
- Inadvertent Entrance Cue: Right after Youngmee says that no suspicious people have been in the pet shop, Jasper and Sue show up.
- Karma Houdini: Buttercream gets the pets into the mess they're in, albeit accidentally, but never tries to help get them out. She is also the only one who remains hostile when everyone else makes peace with each other. In spite of that, she maintains Blythe's trust, and, by the next episode, is on good terms with everyone else.
- Lame Comeback:Russell: [to Pepper] Listen here, smelly pants...Pepper: Who are you calling smelly pants?Russell: I'm calling you a smelly pants.Pepper: Oh, yeah? Well, I'm calling you a...tiny boy.Russell: Tiny boy? That doesn't even make sense.
- Lampshade Hanging: Blythe laments about being a Weirdness Magnet.
- Leitmotif: "The Sweet Shop Song" becomes Sweet Delights's theme for this episode.
- List Song: The choruses in "The Sweet Shop Song" supersede short lists of desserts.
- Madness Mantra: "Sugar sugar sugar sugar..."
- Noodle Incident: Something bizarre happened in the past after Youngmee drank a gallon of coffee.
- Out of Order: The premiere dates for this episode and "Trading Places" were switched, putting "Topped with Buttercream" before it despite being made second. Reasons are difficult to pinpoint, but it was most likely to get Buttercream out sooner to sell toys of her.
- Rack Focus: In a blink-and-you'll-miss-it case, between Buttercream and the caramel apple cherry cream s'more in "The Sweet Shop Song."
- Sanity Slippage: Happens in a rather short order to the pets. They fall completely off the deep end by the middle of Act 2. Something similar happened to Buttercream when the episode begins, and she never recovers from it.
- "The Sweet Shop Song" is done, both the song and the sequence, in the style of early rock from The '50s, particularly Chuck Berry's "Johnny B. Goode." It also resembles the songs from Grease.
- Pepper's series of quick "You know what" exclamations after getting sick may be based on the YouTube Poop "Big Beat Mario."
- So Beautiful, It's a Curse: This is what Penny believes, at least.
- Twitchy Eye: Pepper eventually develops one.
- Unreliable Narrator: The most likely reason Blythe would miss the fact that the pets are completely sick of sweets after hearing Minka's story.