• If you use sourdough, prepare the sweet stiff levain the night before. Mix all ingredients for sweet stiff starter. Cover loosely with a plastic wrap or a lid. It takes about 7-10 hours to triple

Prepare the dough:

• I use approximately 10 cardamom pods. I use a pestle to crack the shells and then get all the seeds out and coarsely grind them with the pestle. You can use a coffee grinder or spice grinder to do so. The coarsely ground is what most Finnish will use in their pulla recipes. It gives a really good and more intense cardamom aroma. Alternatively, you can always use store-bought ground cardamom too for convenience
• Dissolve active dry yeast in warm water in a mixing bowl of a stand mixer. Let it sit for 10 minutes until foamy. If you use instant yeast, you can skip this step
• If you use sourdough, add all of the sweet stiff starter into the mixing bowl of a stand mixer
• Add sugar, salt, ground cardamom, water, and egg. Add the flour. Use the dough hook to stir the mixture a bit so the flour won't fly around when you start the mixer. Knead on the lowest speed for 2-3 minutes and then increase to speed 2 and knead for 3 minutes and then speed 4 for another 3 minutes or until it forms a dough that clears the side of the bowl, but not smooth yet
• Add the softened butter in 3 batches. Once all the butter is in, increase speed to to 4 and knead for 5-8 minutes or until the dough is elastic, smooth, and satiny. Add the raisin and knead at the lowest speed to just distribute the raisins

First proofing:

• Lightly oil the bowl, cover with a kitchen towel or loosely with plastic wrap, and let rise in a warm place for about 45 minutes to 1 hour, or until double in volume. if it's colder, it may take longer to proof the dough
• For sourdough version, it may take 2 - 2 1/2 hours or longer for the dough to double at a warm place. It took mine about 2 1/2 hours

Shaping:

• Transfer the dough to a lightly floured work surface. Knock out all the gas and divide the dough into 3 or 4 portions (for 3 or 4 strands braid). Shape them into oval-ish shape. Cover with a cling wrap to prevent them from drying. Rest for 15 minutes to relax the gluten
• Work with one dough at a time and keep the rest covered. Roll one dough into about 18 inches long. Repeat with the rest of the dough on this first set

For 3 strands:

• Lay the three strands vertically with the farthest ends pinched together. Move the right strand to the middle, then the left strand to the middle. Repeat this motion, right to the middle, left to the middle. You can refer to the photos in this post for better understanding (hopefully!)

  Starting from the middle, braid the strands loosely and work towards either end. Do not stretch the dough while braiding. Pinch the ends together well and tuck under. Place the 2 braids on a large (12 x 16 inches) baking sheet lined with parchment paper or greased well, or use two smaller baking sheets if you want to, one for each braid. Cover with a kitchen towel and let rise again for 45 minutes to an hour

For 4 strands:

• Lay the three strands vertically with the farthest ends pinched together. Take the farthest left strand and move it to the right over 2 strands and then to the left over 1 strand
• Take the farthest right strand and move it to the left over 2 strands and then to the right over 1 strand
• Keep repeating this motion until you reach the end. Pinch the end together and tuck them underneath a bit so they won't come undone during final proofing. You can refer to the photo above or this visual from King Arthur Baking's 4-braided challah tutorial for better understanding if you need to

Final proofing:

• Transfer the braided dough to a large baking sheet for final proofing. Cover the doughs and put in a warm place. This may take 40 minutes to 1 hour or longer for it to be puffy and almost double in size. For sourdough version, allow about 2-3 hours for the dough to be puffy. Preheat the oven to 350 F (180 C) for a conventional oven, 15 minutes before the end of final proofing. Lower the temperature by 20 F or 15 C if you have a convection oven

Baking:

• Mix the egg yolk with the milk and brush the loaves well on all sides. If you plan to put a frosting after baking, you can skip the topping at this stage, otherwise, sprinkle with pearl sugar and chopped almonds along the top. Place the baking sheet on the middle rack and bake the loaves for 25 minutes, or until nicely golden brown. You may need to tent with aluminum foil if it gets browned too fast. Cool on a rack, covered with a kitchen towel for a soft crust

To frost the bread (optional)

• Combine icing sugar and butter. Add the vanilla extract and water to get a thick but spreadable consistency. Add more milk if necessary
• Let the bread cool down completely. Spread the frosting on top and then sprinkle with some chopped nuts