Sometimes you have to educate the customer as to what is possible and what is not. Personally, I would tell them that could only be done with fondant, and that the fondant would have buttercream underneath, so the girl could remove the fondant from hers and it would still have frosting, or they could pick a different design.
I agree with Texas_Rose - I don't think you should bust your arse for something that take too long and not look good in the end.
However, I was typing that, the thought occurred to me that you could do stripes of fondant. Ice the cake in bc. Make the stripes out of fondant and apply them to the sides, leaving every third or fourth (or whatever, based on your design) "empty" to let the bc be the stripe. I realize that it won't be completely flat, but that way the little girl only has to remove a stripe or two from her piece.
It might be a totally dumb suggestion, but, hey, HTH.
I agree with Texas_Rose - I don't think you should bust your arse for something that take too long and not look good in the end.
However, I was typing that, the thought occurred to me that you could do stripes of fondant. Ice the cake in bc. Make the stripes out of fondant and apply them to the sides, leaving every third or fourth (or whatever, based on your design) "empty" to let the bc be the stripe. I realize that it won't be completely flat, but that way the little girl only has to remove a stripe or two from her piece.
It might be a totally dumb suggestion, but, hey, HTH.
I do fondant stripes on buttercream all the time. Just roll the fondant really thin and apply to cake. It makes a nice presentation. The monkey cake in my gallery is iced in buttercream with fondant stripes and polka dots.
Let it crust well then use a piece of kitchen string to mark the lines.
This is what I did for a cake for my daughter. She wanted a Pokemon cake with red, black and white stripes. I crumb coated it, marked the center point, then used a piece of string to lay across and mark the stripes. I imagine this would be very time consuming if you were doing narrow pin stripes. I ended up piping the whole thing in small stars because it looked neater than trying to spread icing into the spaces.
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