In the bowl of a stand mixer, combine the flour, instant yeast, and granulated sugar. Stir with a spoon to blend, then add the salt and mix again. Add the eggs, warm milk, vanilla extract, and melted (but cooled) butter. Using the dough hook, start mixing on low speed until the dough comes together. Increase to medium speed and knead for 8–10 minutes, or until the dough is soft, smooth, and elastic.
Cover the bowl with plastic wrap or a clean towel and let the dough rise in a warm spot for 1–2 hours, or until it doubles (or even triples) in size.
In a medium mixing bowl, combine the room-temperature butter, brown sugar, cinnamon, and Biscoff spread. Mix until a smooth, spreadable filling forms. If the Biscoff spread is too thick, warm it slightly to help it blend. Once the dough has doubled in size, gently punch it down to release the air. Transfer the dough to a lightly floured surface and roll it into a large rectangle, about ¼ inch thick.
Spread the filling evenly over the rolled dough, covering the entire surface from edge to edge. Starting from the long side, tightly roll the dough into a log.
Use a sharp knife or unflavored dental floss to slice the log into even rolls, about 1 ½ inches thick. Place the rolls into a greased or parchment-lined 9×13-inch baking pan, leaving a little space between each one. Cover the pan loosely with plastic wrap or a clean towel and let the rolls rise for 30–45 minutes, or until doubled in size and puffy. Meanwhile, preheat your oven to 180°C (350°F).
Bake the rolls for 20–25 minutes, or until lightly golden on top and cooked through. Avoid overbaking to keep them soft and gooey.
While the rolls cool slightly, make the Biscoff cream cheese frosting: beat the butter and cream cheese until smooth, then add the vanilla, salt, powdered sugar, and Biscoff spread. Mix until creamy.
Frost the warm rolls generously with the cream cheese frosting so it melts slightly into all the layers.
Then drizzle or spread extra Biscoff spread on top of each roll and finish with crushed Biscoff biscuit crumbs for extra crunch and flavor.