In a stand mixer bowl, combine warm milk and yeast with 1 tablespoon sugar; let stand 5 minutes until frothy. Add remaining sugar, crushed cardamom, salt, and half the flour.

Fit mixer with dough hook and knead on low, gradually adding remaining flour. Add softened butter one tablespoon at a time until incorporated. Knead for 8 to 10 minutes until dough is smooth, elastic, and pulls away from bowl sides.

Cover bowl with damp towel; let rise in warm spot for 1 hour until doubled in size.

Make filling by beating softened butter, brown sugar, crushed cardamom, and cinnamon until creamy.

Roll dough on lightly floured surface into a 14x20-inch rectangle. Spread cardamom butter evenly over entire surface. Fold dough into thirds like a business letter.

Cut dough into 12 even strips (about 1 inch wide). Cut each strip lengthwise down center, leaving top attached. Twist the two strands together, wrap into an intricate knot, and tuck ends underneath. Place on parchment-lined baking sheets.

Cover loosely and let rise 30 minutes. Bake at 400°F (200°C) for 12 to 14 minutes until deep golden brown.

Immediately brush hot buns with warm simple sugar syrup. Sprinkle generously with Swedish pearl sugar and coarsely crushed cardamom. Serve warm for traditional Swedish fika!