you cant do anything in powdered sugar while hot or wet.
think of a powdered doughnut in a package. if that package gets moist, think about what happens. same w/ heat, the sugar will just disappear.
set the doughnut on a wire cooling rack, let them cool a tad. not saying they must be cold, but not blistering hot, just warm.
then you can either dust them, or fill a lunch sack about a 4th to a 3rd up, dump in a few depending on size and shake.
eat!!
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