The last time I sugar dusted my hives, I used 1 cup of powdered sugar for each deep and separated the deeps. I don't have any honey supers on right now - just the 2 brood deeps.
Can I just pull the top off, sprinkle 2 cups into the top box, brush it off between the frames and button her back up? I use screened bottom boards on both and will install the trays to catch and count the mites. Not having to pull the upper deep off will save my back, but if it is not as effective a treatment, then I will do it.