Mix the warm milk with the granulated sugar and active dry yeast in a large bowl. Allow to rest for about 5 minutes until frothy.
Incorporate the melted butter and egg, whisking until combined.
Gradually fold in the flour and salt, stirring until a cohesive dough forms.
Transfer the dough to a floured surface and knead for 5-7 minutes until smooth and elastic.
Place the kneaded dough into a greased bowl, cover with a kitchen towel, and let rise in a warm area for about 1 hour or until doubled in size.
Preheat the oven to 350°F.
Roll out the dough on a floured surface into a rectangle measuring about 12x18 inches.
Spread the Biscoff cookie butter generously across the surface of the dough.
In a separate bowl, combine the brown sugar and cinnamon, then sprinkle evenly over the cookie butter layer.
Roll the dough tightly from one long edge to the other, forming a log.
Slice the log into 12 equal pieces and arrange them in a greased 9x13-inch baking dish.
Cover the dish with a towel and let the rolls rise for an additional 30 minutes.
Bake the rolls in the preheated oven for 20-25 minutes, or until golden brown.
Prepare the glaze by mixing the powdered sugar with 1-2 tablespoons of milk until smooth.
Drizzle the glaze over the warm cinnamon rolls and enjoy!