In a large bowl, whisk together the flour, granulated sugar, salt, and instant yeast.

Stir in the warm milk, melted butter, and egg until a shaggy dough forms. Knead by hand or with a stand mixer for 5-7 minutes until smooth and elastic.

Place the dough in a greased bowl, cover with a warm towel, and let rise in a warm place for about 60 minutes or until doubled in size.

In a small bowl, mix the brown sugar, cinnamon, cardamom, ginger, cloves, and black pepper.

Punch down the dough and roll it out on a floured surface into a 12x16 inch rectangle. Spread the softened butter over the dough and sprinkle evenly with the chai sugar mixture.

Roll the dough tightly starting from the long edge. Cut into 8 equal rolls and place them in a greased 9x13 inch baking dish.

Cover and let rise for another 30 minutes while preheating your oven to 350°F (175°C).

Bake for 20-25 minutes until golden brown. While baking, whisk the powdered sugar, milk, and vanilla extract to make the glaze.

Remove buns from the oven and drizzle with the glaze while they are still warm. Serve immediately.