For years, baking blogger Amanda Rettke has given her readers new ways to “Let them eat cake.” Now, the suburban Minneapolis resident has just had her first cookbook published, Surprise-Inside Cakes: Amazing Cakes for Every Occasion – with a Little Something Extra Inside (William Morrow, Mar.). Rettke is a master at creating cakes that yield edible surprises hidden inside. Rainbows, cherries, hearts, holiday candles – imagine Russian nesting dolls, only made with cake and frosting.

According to her editor at William Morrow, Cassie Jones, the publisher was “charmed” by Rettke’s vision of “what’s possible within a cake.”

“If you break down the process, there’s nothing particularly difficult about making these cakes,” said Jones. The cookbook, which includes both professional photographs and those Rettke took, walks readers through each step, allowing them to “think backward, forward, and three-dimensionally,” as Jones put it, while creating a surprise-inside cake.

Rettke attributes her career baking and decorating cakes to her five children, the first of whom was born 10 years ago, the youngest 10 months ago. She started a blog a decade ago called “i am mommy,” which evolved into an “i am baker” blog in the last five years, as she found herself baking birthday cakes and cookies for (and with) her growing family. The blog has 12,000 subscribers and averages around two million page views per month. Rettke also teaches online cooking classes for Craftsy; her sessions are filmed in a Denver television studio.

“I want people to look at my cakes and feel joy,” Rettke said about her technique, which involves baking a cake, then cutting out a portion, crumbling it, and mixing it with buttercream icing before shaping it. She then reassembles and frosts the cake.

“My skill is sharing my creativity with others,” she said, “Please don’t watch my cake frosting technique. Watch my joy.”

To date, cake-lovers have only had one opportunity to watch Rettke demonstrate her joy in person. While she launched her cookbook with a March 20 Q&A and book signing at Magers & Quinn Booksellers in Uptown Minneapolis, the cupcakes she shared with the audience of 20 to 30 people were baked earlier. Magers & Quinn sold 14 copies of Surprise-Inside Cakes that evening; events coordinator Ann Mayhew said that literature and cookbooks are the bookstore’s two topselling categories.

A picture is worth 1,000 words, and seeing is believing: Rettke certainly demonstrated these two truisms at her March 28 appearance at the Kitchen in the Market, which operates in the Midtown Global Market, a commercial building packed with ethnic food shops and cafes in Minneapolis. The 35 attendees not only watched Rettke decorate a surprise-inside cake, but also got to try their hands at frosting cupcakes using Rettke’s techniques.

“Who doesn’t love playing with frosting?” said Tracy Morgan, the Kitchen in the Market’s co-owner; a copy of Rettke’s cookbook was included with the price of admission to the event.

While Rettke isn’t quite used to the idea of demonstrating her cake-baking in front of a live audience, especially one with members who aren’t shy about asking questions and making comments, she is taking it all in stride. “My kids are a tougher audience than anyone else,” she said.