Crush the Biscoff cookies into fine crumbs.
Combine the crumbs with melted butter until evenly moistened.
Press firmly into the bottom of a 9-inch springform pan and refrigerate while preparing the filling.
Beat the softened cream cheese until completely smooth.
Add the powdered sugar, vanilla, and salt and beat until combined.
Add the Biscoff spread and mix until smooth.
In a separate cold bowl, whip the heavy cream until stiff peaks form.
Gently fold the whipped cream into the cream cheese mixture in several additions.
Transfer the filling onto the chilled cookie crust.
Spread evenly and smooth the surface.
Cover and refrigerate for at least 6 hours, preferably overnight.
Gently warm the Biscoff spread for the topping just until pourable.
Pour it over the completely chilled cheesecake and gently spread across the surface.
Refrigerate for another 20–30 minutes.
Decorate with Biscoff cookie crumbs, broken cookies, and whipped cream if desired.
Slice with a warm clean knife and serve chilled.