Line a 12-cup muffin tin with paper liners. In a medium bowl, combine 1.5 cups (150g) of finely crushed Biscoff cookies with 4 tbsp (56g) of melted unsalted butter. Stir until it resembles wet sand. Press 1 heaping tablespoon of the mixture tightly into the bottom of each liner.

In a chilled mixing bowl, beat 1 cup (240ml) of cold heavy whipping cream on medium-high speed until stiff peaks form. Set aside in the refrigerator.

In a large bowl, beat 16 oz (450g) of room-temperature cream cheese until smooth. Add 1/2 cup (120g) of Biscoff cookie butter, 1/2 cup (60g) of powdered sugar, and 1 tsp (5ml) of vanilla extract. Beat until smooth and light caramel in color. Gently fold in the whipped cream until no white streaks remain.

Spoon or pipe the filling evenly over the prepared crusts. Smooth the tops so they are flat. Chill in the refrigerator for at least 4-6 hours.

Melt the remaining 1/2 cup (120g) of Biscoff cookie butter in the microwave in 15-second intervals until pourable. Spoon over the chilled cheesecakes, flooding the surface evenly. Chill for 15 more minutes.

Remove paper liners. Garnish each mini cheesecake with an upright Biscoff cookie half and a fine dusting of cookie crumbs. Serve immediately.