In a small bowl, combine the warm milk, granulated sugar, and active dry yeast. Let it sit for about 5-10 minutes, or until the yeast is frothy.
In a large bowl, whisk together the flour, salt, and ground cardamom (if using).
Make a well in the center of the dry ingredients and add the yeast mixture, softened butter, and eggs. Mix until a dough forms.
Transfer the dough to a floured surface and knead for about 5-7 minutes, or until smooth and elastic.
Place the dough in a greased bowl, cover with a clean kitchen towel, and let it rise in a warm place for about 1-1.5 hours, or until doubled in size.
Punch down the risen dough and transfer it to a floured surface. Roll out the dough into a large rectangle. If desired, sprinkle raisins and chopped nuts evenly over the dough. Roll it up tightly, then form a circle with the roll and pinch the ends together to seal.
Place the dough ring on a parchment-lined baking sheet. Cover with a kitchen towel and let it rise for about 30-45 minutes.
Preheat your oven to 350°F (175°C).
Brush the surface of the dough ring with the beaten egg.
Bake in the preheated oven for 25-30 minutes, or until golden brown.
Allow the Kliņģeris to cool on a wire rack. Once cooled, dust with powdered sugar.
Slice and serve as a sweet treat with coffee or tea.
Enjoy your meal!