Mix yeast with two-thirds cup of warm water, then set aside until ready.
Combine the bread flour, rye, and salt in a stand-mixer bowl or a regular bowl if you are kneading by hand.
Add the softened butter and the yeast mixture; mix until you start forming a dough, then add the raisins.
Continue mixing (kneading) until you get a smooth dough for your Swedish rye rolls. (Note: It's not a sticky dough.) Form it into a ball, place it in an oiled bowl, then cover it with a clean kitchen cloth until it doubles in size (usually an hour and a half for me).
Divide it into eight portions and form each piece into a ball.
Place them in a baking tray lined with parchment paper and keep some space between them.
Cover with a cloth again until they become puffy --- at least thirty minutes.
Preheat the oven to 230°C (425°F).
Uncover your Swedish rye buns and dust them with flour.
Once the oven is ready, place the baking tray in the middle of the oven.
Adjust the temperature to 200°C (375°F) and continue baking your rye buns for twenty to twenty-five minutes or until golden brown.
Remove from the oven and transfer to a rack to cool.
Serve and enjoy with your favorite marmalade!