In a small bowl, stir together 2 tablespoons of the brown sugar, milk and yeast.

Let sit until very foamy, about 10 minutes.

In a large bowl, whisk together all-purpose flour, pastry flour, orange zest and salt.

Add yeast mixture, 2 tablespoons of the butter and egg and stir to form a shaggy dough.

Turn out onto a floured surface and knead until smooth and elastic, about 5 minutes.

Lightly butter a large, clean bowl.

Place dough in the bowl, cover with plastic wrap and let sit in a warm spot until doubled in size, about 1 hour.

Lightly butter a 12-cup muffin pan.

Turn dough out onto a floured surface and roll into a 14x16-inch rectangle.

Gently spread remaining 2 tablespoons butter over dough.

In a small bowl, stir together cinnamon and remaining 1/2 cup plus 2 tablespoons brown sugar.

Sprinkle over dough, leaving a 1-inch border around edges.

Starting with a long side, snugly roll up dough 1 inch at a time, pulling and stretching it away from you a bit with every roll.

Place seam side down and use a serrated knife to cut into 12 rolls, trimming off the ends, if you like.

Transfer to the prepared muffin cups.

Cover loosely with plastic wrap and refrigerate for 8 hours or overnight. Alternatively, skip refrigeration and proceed to the next step.

Let rolls sit at room temperature for 1 hour.

During the last 15 minutes, preheat the oven to 350°F.

Uncover and bake rolls until puffed and golden brown, 18 to 20 minutes.

Remove from the oven and cover with a clean kitchen towel for 10 minutes to let soften.

Meanwhile, in a small bowl, whisk together powdered sugar and orange juice.

Carefully remove warm rolls from the pan, drizzle with orange icing and serve.