One at a time, quickly dip Biscoff cookies into the espresso mixture for 1 second on each side.
Arrange the soaked cookies into one layer in the bottom of the baking dish.
Take half of the whipped cream mixture and spread it evenly on top of the soaked cookies.
Repeat the 3 steps above to make another layer by soaking cookies, making one layer on top of the whipped cream mixture, and topping with the remaining whipped cream mixture, spreading evenly. (Note - Some cookies can be split in halves to fill any empty spaces.)
Refrigerate uncovered for 2 hours.
After chilling, dust the top of the tiramisu with cocoa powder. Cover the pan with plastic wrap and refrigerate for at least 2 additional hours.
To serve, either cut into the tiramisu with a knife to make slices, or use a spoon to make scoops. Be sure to wipe the knife spoon clean between each serving to make for cleaner cuts/scoops.