In the bowl of a stand mixer, add the warm milk, yeast, and sugar. Lightly whisk together, then allow to sit for 6 minutes to activate the yeast.
Add the egg, salt, and butter. Whisk to combine, mainly to break up the egg.
Place the dough hook on the mixture. Add in the flour. Knead the dough on LOW for 2 minutes. Increase speed to Medium-High to knead for 5 more minutes. The dough should be soft and pliable. Adjust with milk (if too dry) or flour (if too sticky). The dough should pull away from the sides of the bowl.
Cover with plastic wrap and allow to rest for 10 minutes.
Meanwhile, preheat the oven to 200 degrees.
Before rolling out the dough, spray the area with non-stick cooking spray where you plan to roll out the dough. Roll out the dough 12″x18″ rectangle, about 1/4″ thick.
For the filling: In a small microwave safe mixing bowl, add the Biscoff spread and butter. Microwave for 6 seconds. This will soften both of them enough to mix in easier with the brown sugar.
Add in the borwn sugar and cinnamon and mix until it forms a paste. Spread the mixture evenly over the dough.
Roll up the dough tightly from the long side. Cut the cinnamon rolls using a serrated knife to be 1 1/2″ – 2″ thick slices. Place into a lightly greased 9×13 inch baking dish. Cover with plastic wrap.
Your oven should be preheated to 200 degrees now. Turn the oven OFF and place the cinnamon rolls in the heated oven to rise 20 minutes.
After 20 minutes, REMOVE the Saran Wrap. Then place back into the oven uncovered.
Leaving them in the oven, turn the oven ON to 375 degrees. Bake for 18-20 minutes, until brown on top.
For the frosting: In a mixing bowl, beat all the ingredients together until well combined.
Allow the rolls to cool for 10 minutes after baking. Place a dollop of the frosting on top of each roll. Then carefully spread the frosting out to evenly cover the rolls. Serves 12.