Melt the butter in a pot.
Warm up the milk to 37°C and add it to the melted butter. Dissolve the yeast and add it to the rest of the liquid ingredients. Mix well until the yeast is completely dissolved.
Mix the saffron with 1-2 tsp sugar and add to the liquid ingredients.
Add the rest of the solid ingredients to the mixture, but save 1 cup of flour for kneading.
Knead until you form a sticky dough (5 mines in the food processor or 10 mins. by hand). Add more flour to the dough in case it is too sticky, but let it be rather loose.
Cover the dough with a cloth and let it double for 40 minutes.
Knead again on a board covered with flour and then split it into 40 pieces. Form long stripes out of the smaller bits of dough and then roll up the ends of each stripe until an S-shaped piece bun is formed. Garnish with raisins or currants.
Place the buns in a baking board covered with baking paper, cover with a cloth and let rise for 40 minutes.
Heat up the oven to 200 degrees
Bake the lussekatter at 180 C for 8-10 minutes.