Brownie cakepop frosting

I'm planning on making some brownie cake pops because it will be very chocolate heavy I'm going to hollow them out a small bit and making a citrus based filling/frosting. I'm leaning towards orange but lemon would work too. I'll be covering them with chocolate when they're filled.

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My questions are regarding the frosting. Will standard butter cream frosting be the best for this and will it survive sitting at ambient temperatures for around 4-6 hours.

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