On as in sprinkled on before she eats a slice, or in as while she is making the dough?
If she puts it in the dough: "Hun putter krydderier i sit rugbrød."
On as in sprinkled on before she eats a slice
hvad krydderier skal hun putter pa rugbrod?
If "sit" refers to the subject, why isn't it "sin"?
It refers to the bread, and because it is "et rugbrød" it is "sit rugbrød". Hope this answers your question.
"krydderier" also means condiments. How is this wrong?
Gonna love this section. Yum.
Is this a thing people in Denmark actually do, or just duo sentence?
"tilføjer" or "lægger" would work much better here than "putter", which is actually more like "tuck in" (like tuck a child into bed). Unless you're ramming spices onto the bread.