In a large mixing bowl, whisk together 4 cups of all-purpose flour, 1/4 cup granulated sugar, 1 packet of instant yeast, and 1 teaspoon fine sea salt.

In a small saucepan, gently heat 1/2 cup of unsalted butter and 1 cup of whole milk until warm but not hot. Add in 1 large egg, then pour this mixture into the dry ingredients.

Knead until smooth, about 5-7 minutes, then let the dough rise in an oiled bowl for 40 minutes until doubled in size.

While the dough is rising, prepare the filling. In a medium bowl, combine 1/4 cup granulated sugar, the freshly zested peel from 2 oranges, 1 teaspoon ground cardamom, and a pinch of salt.

Once the dough has risen, turn it onto a lightly floured surface. Roll into an 18x12-inch rectangle, spread 1/4 cup softened unsalted butter, followed by the filling.

Roll the dough tightly into a log, cut into strips, twist and tie them into bun shapes, and place on a parchment-lined baking sheet.

Cover with a towel and let rise for another 25-30 minutes. Preheat oven to 375°F (190°C).

Bake the buns for 17-18 minutes until golden brown.

For the glaze, combine 1 orange juice, 1/2 cup granulated sugar, and 1/2 teaspoon ground cardamom. Heat until dissolved and brush over warm buns.