- Lily Plankton (debut)
- Sheldon J. Plankton
- SpongeBob's great grandma
- Eugene H. Krabs
- SpongeBob SquarePants
- Gary the Snail (cameo in picture)
- Incidental 82
- Incidental 93
- Old Man Jenkins (cameo)
- Incidental 81
- Incidental 84
- Miss Gristlepuss (cameo)
- Granny (cameo)
- Incidental 92
- Incidental 85
- Squidward Tentacles
- King Neptune (mentioned)
In the beginning at Shady Shoals Rest Home, Plankton is with his grandmother, who is lying down on a bed. After thinking of what to do with her, Plankton puts his grandmother to sleep, and then takes some of her clothes to wear.
Plankton later walks over to SpongeBob's house, where he appears. Plankton says that he is his great grandmother, in which he actually believes so. SpongeBob gives his "great grandmother" a tour of his house and shows Plankton all of his albums. The next day, Plankton wants to go to the Krusty Krab, but SpongeBob insists that they go to a nursing home instead. There, they knit and play cards, when Plankton rips a card in annoyance at SpongeBob's antics.
SpongeBob realizes he is bored and decides to take him to the Krusty Krab, although Plankton says he wants to enter through the back door.
Meanwhile, Plankton ties up a balloon that looks like him. It flies away into the dishwasher, and when SpongeBob turns it on, the balloon pops. SpongeBob, thinking it is his great grandma, cries, but then Plankton re-appears and says he is fine. After, Plankton tells SpongeBob that he is tired and needs to take a nap in a private place. SpongeBob agrees and takes him to the safe. Thereafter, Plankton's grandma walks inside of the Krusty Krab and finds out what Plankton is secretly plotting. She takes him back while SpongeBob thinks that his own great grandma caught Plankton trying to steal the formula.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
• A Pineapple Luau - Nicolas Carr, Sage Guyton, Jeremy Wakefield [Title card]
‣ Happy Home - Harry Bluestone, Emil Cadkin [opening at Shady Shoals]
‣ Epic Struggle - Fredric Bayco [Plankton puts his grandma's teeth in his mouth]
‣ Sweet and Lovely - Alan Braden [Plankton's daydream]
‣ Dramatic Impact (6) - Ivor Slaney [Plankton laughs evilly]
• Salty Squid Jig 2 - Michael Bolger, Nicolas Carr, Sage Guyton, James King [SpongeBob taking a bath]
‣ Sea Battle [#45] - John Fox ["Threat neutralized, Captain."]
‣ Sea Battle [#48] - John Fox ["Uh-huh. Right away, Captain. All hands, prepare to dive!"]
• Steel Licks 4 - Jeremy Wakefield [SpongeBob answers the door]
• My Three Fish - Nicolas Carr, Barry Anthony [Plankton disguised as an old lady]
• Great Idea Patrick - Nicolas Carr [SpongeBob gets an idea]
• Steel Licks 37 - Jeremy Wakefield [Plankton stuck in the pillow]
‣ Hawaiian Party - Peter Dennis [looking at old photo albums]
• Steel Licks 6 - Jeremy Wakefield [the next morning]
• Tip Toe Through the Seaweed - Nicolas Carr, Barry Anthony [SpongeBob wakes Plankton up]
• Closing the Door Sting - Nicolas Carr [Plankton laughs]
‣ Holiday Playtime - Cedric King-Palmer [Plankton puts on lipstick]
• Flashback - Nicolas Carr [Flashback begins]
‣ Vibraphone, "I've Been Hypnotized!" - Sound Ideas [during flashback]
‣ ? [chimes]
• Flashback - Nicolas Carr [Flashback ends]
‣ Holiday Playtime - Cedric King-Palmer ["No, you couldn't possibly care about any of that stuff."]
‣ Lambs in Clover - Jack Strachey [Grandma's Tea House]
‣ Cocksure Capers - Phil Green [card game]
‣ Domestic Fun (A) - Ernest Tomlinson [SpongeBob takes Plankton to the Krusty Krab.]
‣ Domestic Fun (C) - Ernest Tomlinson [Plankton screams]
• Unknown Goofy Cue - Nicolas Carr, Barry Anthony ["You have been warned about lurking back here on your days off."]
• What's This - Nicolas Carr [Plankton's gone]
• Unknown Goofy Cue - Nicolas Carr, Barry Anthony [Squidward taking out the trash]
‣ Domestic Fun (B) - Ernest Tomlinson [Plankton in the garbage can]
• Nautical Hijinx - Nicolas Carr, Barry Anthony [SpongeBob takes Plankton into the kitchen]
‣ Apprehensive 2 - Harry Bluestone, Emil Cadkin [Plankton inflates decoy]
• Nautical Hijinx - Nicolas Carr, Barry Anthony [SpongeBob turns on the garbage disposal]
‣ Dramatic Impact (5) - Ivor Slaney ["Grandma!"]
‣ Epilog - Gerhard Trede [SpongeBob crying]
• Vibe Q Sting - Nicolas Carr ["SpongeBob, up here!"]
• My Three Fish - Nicolas Carr, Barry Anthony [SpongeBob puts Plankton in Krabs' safe]
‣ Zelle 501 - Gerhard Trede [Plankton finds the formula]
‣ Dramatic Impact (6) - Ivor Slaney [Plankton gasps]
• A Pineapple Luau - Nicolas Carr, Sage Guyton, Jeremy Wakefield [Ending]
- This episode is available on the SpongeBob's Frozen Face-Off (UK version only), The Best 200 Episodes Ever, The SpongeBob SquarePants Collection, Season 7 Volume 2, The Krabby Patty Recipe Theft, The SpongeBob SquarePants 8 Season DVD Collection, SpongeBob SquarePants Vol. 11, Sunđer Bob Kockalone DVD 6, Complete Seventh Season, and Next 100 Episodes DVDs.
- "Gramma's Secret Recipe" was ranked #60 during the SpongeBob's Top 100 event in the UK and Ireland from June 4-8, 2012.
- Miss Gristlepuss from "Banned in Bikini Bottom" and Granny from "Have You Seen This Snail?" appear while SpongeBob and "Great Grammie Ma" are knitting.
- Irony: It would have made more sense for Plankton to steal the formula himself (like in his vision) than to pretend to be SpongeBob's grandma.
- This episode premiered during the SpongeBob and the Clash of Triton event.
- The scene where Plankton pulls out, stretches, and blows up a green balloon that is a decoy of him is a possible reference to the scene in "Truth or Square" of when Mr. Krabs blew Plankton up like a balloon and letted him float away.
- SpongeBob said a similar line in "Gone," when he said, "So it was true..."
- Lily Plankton reappears in the episode "Grandmum's the Word."
- However, her glasses only have one lens in that episode, while in this one, they have two.
- This is the first episode where "A Pineapple Luau" plays.
- It is unknown how Plankton's grandma figured out that Plankton was at the Krusty Krab.
- This episode is similar to "Imitation Krabs", and "Someone's in the Kitchen with Sandy", as both episodes involve Plankton impersonating a character in order to get the Krabby Patty secret formula.
- Coincidentally, "Someone's in the Kitchen With Sandy" and "Grandma's Secret Recipe" are both in the same season, which is season 7.
- In the opening and closing credits, Laraine Newman's name is misspelled as "Loraine Newman."
- When Plankton pulls down his antennae, they are quickly stuck back up when SpongeBob and Plankton are walking together.
- When Plankton is turned into a scarf, he has two eyes.
- There is chocolate on the pillow and blanket, but when Plankton laughs, it is gone.
- In American airings, after Plankton steals his grandma's clothes and hair, she still has hair, but at the end, she is bald when she comes to take it back.
- Whenever Plankton takes off the glasses, his one eye disappears when he puts them back on and off.
- The balloon "Grannie Ma" should have popped when it went in the garbage disposal, but is slowly cut up.
- When SpongeBob and Plankton play cards, the animation cell for the table in the background is above SpongeBob's, so parts of his left hand are erased multiple times when it goes near the table.