01 - Combine flour, sugar, yeast, and salt in a large mixing bowl. Add warm milk, warm water, melted butter, and egg. Mix thoroughly until a shaggy, sticky dough forms.
02 - Turn dough onto a lightly floured surface and knead by hand for 8–10 minutes until smooth and elastic. Alternatively, use a stand mixer with dough hook attachment for 6–7 minutes on medium speed.
03 - Place dough in a greased bowl, turning once to coat all sides. Cover with plastic wrap or a clean towel and let rise in a warm, draft-free area for 1 hour until doubled in volume.
04 - Punch down risen dough to release air. Roll out on a lightly floured surface into a 16x12-inch rectangle. Mix softened butter and Biscoff spread until creamy and spread evenly over dough, leaving a small border. Sprinkle brown sugar and cinnamon uniformly across the surface.
05 - Starting from the long edge, roll dough tightly into a log. Using a sharp knife or unflavored dental floss, slice into 12 equal rolls approximately 1 1/2 inches thick.
06 - Arrange rolls in a greased 9x13-inch baking dish, leaving space between each. Cover loosely and let rise for 45–60 minutes until puffy and nearly doubled in size.
07 - Preheat oven to 350°F. Bake rolls for 22–25 minutes until golden brown on top and cooked through. The center should spring back when lightly touched.
08 - While rolls bake, whisk melted Biscoff spread, powdered sugar, and 2 tablespoons milk until smooth and creamy. Add additional milk 1 teaspoon at a time if needed to achieve drizzling consistency.
09 - Drizzle warm Biscoff glaze generously over rolls immediately after removing from oven. Serve warm for optimal texture and flavor.