Combine warm milk, sugar, yeast, and salt in a bowl. Let stand 5–10 minutes until frothy. Add melted butter and egg, then gradually stir in flour. Knead for 6–8 minutes until soft and elastic. Cover and let rise for 1 hour or until doubled.

Roll dough into a large rectangle. Spread melted butter, then a generous layer of Biscoff cookie butter. Mix brown sugar and cinnamon and sprinkle evenly over the dough.

Roll dough tightly into a log. Slice into 8–10 rolls and place in a greased baking dish. Cover and let rise 30 minutes until puffy.

Bake at 350°F (175°C) for 20–25 minutes until golden and set. Pour warm melted Biscoff cookie butter over the rolls and finish with crushed Biscoff cookies.