The 22-year-old, who tied the knot with her long-term boyfriend Jamie Watson last week, headed to her all-time favourite bakery The Cocoa Bean to commission the cake.
Shop owner Anthony Delpidio was tasked with creating the five-tiered masterpiece. Jamie Lynn chose a traditional vanilla, almond and vanilla-bean buttercream cake, which took eight hours to make.
"For the wedding consultation she was actually out of town," Anthony told People. "She sent a picture and said, 'This is the idea I want. Just run with it and do your thing.'
"She's not a very tough customer. She's very easygoing. I think she just wanted to keep it simple."
As for the groom's cake, 31-year-old Jamie — a fishing aficionado — looked to his passion for inspiration.
"Jamie's idea was to have his [duck-hunting] boat and his dog on there," said Anthony of the chocolate cake with chocolate buttercream frosting. "He sent me pictures of the boat and we worked off of that."
More photos from the couple's wedding here
Jamie and Jamie Lynn wed in a romantic ceremony surrounded by their nearest and dearest, including older sister Britney and the singer's two boys Sean, 8, and seven-year-old Jayden James.
Britney congratulates her newlywed sister
Jamie Lynn's five-year-old daughter Maddie also played a starring role as a bridesmaid on the day and looked adorable in her white floral embroidered frock.
More details of the March nuptials are emerging. Earlier this week, the boutique where Jamie Lynn bought her wedding dress posted photos of the stunning bride at the reception.
In the snapshot, Jamie Lynn is pictured posing with her mother in a strikingly similar ivory gown. The new bride looks like she's having the time of her life, grinning widely as she enjoys the tunes on the dancefloor.
Photos of the cake courtesy of The Cocoa Bean.