Stir the ground Biscoff cookies with the melted butter until evenly moistened. Press firmly into the bottom of a 7-inch/18 cm springform pan, creating a compact, even layer. Chill while preparing the filling.
Beat the cream cheese and powdered sugar on medium speed until completely smooth, about 2 minutes, scraping the bowl once to ensure no lumps remain. Spread evenly over the chilled crust and smooth the top. Freeze until firm, about 2 hours.
Warm the Biscoff spread in the microwave just until fluid, 30 to 60 seconds. Pour over the frozen cake, tilting the pan so the topping reaches the edges in an even layer. Refrigerate until set, about 15 minutes, before slicing.