01 - Combine flour, sugar, yeast, and salt in a large mixing bowl. Ensure ingredients are evenly distributed.
02 - Add warm milk, warm water, melted butter, and egg to the dry mixture. Stir until a shaggy, sticky dough forms.
03 - Turn dough onto a floured surface and knead for 8-10 minutes until smooth and elastic. Alternatively, use a stand mixer with dough hook for 6-7 minutes.
04 - Place dough in a greased bowl, cover with plastic wrap or towel, and let rise in a warm place for 1 hour until doubled in size.
05 - Punch down risen dough and roll out on a lightly floured surface to a 16x12-inch rectangle.
06 - Mix softened butter and Biscoff spread until creamy and well combined. Spread evenly over the rolled dough, leaving a small border at edges.
07 - Sprinkle brown sugar and ground cinnamon evenly over the Biscoff mixture.
08 - Roll up dough tightly from the long edge. Slice into 12 equal rolls using a sharp knife or unflavored dental floss.
09 - Arrange rolls in a greased 9x13-inch baking dish. Cover and let rise for 45-60 minutes until puffy and nearly doubled.
10 - Preheat oven to 350°F.
11 - Bake rolls for 22-25 minutes until golden brown on top and cooked through. Edges should be lightly golden.
12 - Whisk melted Biscoff spread, powdered sugar, and 2 tbsp milk until smooth. Add additional milk 1 tsp at a time if needed for drizzling consistency.
13 - Drizzle warm glaze over rolls immediately after removing from oven. Serve while warm for best texture and flavor.