Collocations for bun - noun

fresh
cinnamon (esp. AmE)
cream, currant, hot cross, iced, sticky (all BrE)
hamburger, hot-dog

eat, have
bake, make, toast

neat, severe, tight
loose, messy

in a bun
a woman with her hair tied back in a loose bun

into a bun
She pulled her hair back into a messy bun.