01 - In a large bowl, combine flour, sugar, yeast, and salt. Whisk until evenly distributed.
02 - Add warm milk, warm water, melted butter, and egg to the dry ingredients. Mix with a wooden spoon until a shaggy dough forms.
03 - Knead on a lightly floured surface for 8 to 10 minutes until smooth and elastic, or use a stand mixer with a dough hook for 6 to 7 minutes on medium-low speed.
04 - Place dough in a lightly greased bowl, turning to coat all sides. Cover with plastic wrap or a damp towel and let rise in a warm, draft-free place for 1 hour or until doubled in size.
05 - Punch down dough to release air. Turn onto a lightly floured surface and roll into a 16x12-inch rectangle.
06 - In a small bowl, mix softened butter and Biscoff spread until creamy and well combined.
07 - Spread the Biscoff mixture evenly over the rolled dough, leaving a small border at the edges. Sprinkle brown sugar and cinnamon evenly over the surface.
08 - Starting from one long edge, roll up dough tightly into a log. Using unflavored dental floss or a sharp knife, slice into 12 equal rolls.
09 - Arrange rolls in a greased 9x13-inch baking dish. Cover and let rise in a warm place for 45 to 60 minutes until puffy and nearly doubled.
10 - Preheat oven to 350°F.
11 - Bake rolls for 22 to 25 minutes until golden brown and cooked through. The center should spring back when lightly touched.
12 - While rolls bake, whisk melted Biscoff spread, powdered sugar, and 2 tbsp milk until smooth. Add additional milk 1 tsp at a time if needed to reach drizzling consistency.
13 - Drizzle warm glaze evenly over the rolls immediately after removing from the oven. Serve warm for best texture and flavor.