Activate the yeast

• Warm the milk until lukewarm.
• Stir in the sugar and yeast and let sit until foamy.

Make the dough

• In a large bowl or stand mixer, combine the milk mixture, melted butter and egg and mix until the egg is lightly beaten in.
• Add the flour and salt and mix until a dough forms.

Knead the dough

• Knead until the dough is smooth and elastic.

Let the dough rise

• Place the dough in a lightly greased bowl, cover, and let rise in a warm spot until doubled in size.

Make the Biscoff filling

• Mix the softened butter and Biscoff cookie butter until smooth.
• Add the brown sugar, cinnamon and salt and mix until combined; the filling should be soft and spreadable, not runny.

Prepare the pan and roll out the dough

• Grease a 9-inch springform pan and line the bottom with parchment paper.
• Roll the dough into approximately a 12 × 16-inch rectangle.

Fill and cut into strips

• Spread the Biscoff filling evenly over the entire surface, leaving a small border around the edges.
• Using a sharp knife or pizza cutter, cut the filled dough into long strips (about 12).

Shape the giant spiral roll

• Roll the first strip into a spiral, then wrap the next strip around it, adding strips one at a time until you have one large cinnamon roll.
• Keep the spiral snug but don't pull or compress the dough, so the layers touch without being squeezed.
• Carefully transfer the roll into the prepared springform pan and finish adding the strips.

Second rise

• Cover the pan and let the roll rise until the dough looks noticeably puffy and airy and the whole cake has visibly expanded.

Bake

• Preheat the oven to 350°F (180 °C).
• Bake, checking the center and middle rings for doneness.
• If the top browns too much before the center is baked, loosely tent the cake with aluminum foil and continue baking.

Cool in the pan

• Let the cake cool in the pan before removing the springform ring.

Make the Biscoff cream cheese frosting

• Beat the softened cream cheese and butter until smooth.
• Add the Biscoff cookie butter, vanilla and salt and mix until combined.
• Gradually add the powdered sugar and mix until smooth, then add the heavy cream a little at a time until smooth and spreadable.

Frost and serve

• Spread the Biscoff cream cheese frosting over the cinnamon roll while it is still slightly warm.
• Finish with crushed Biscoff cookies and serve warm and gooey.