Pulse 250g of Biscoff cookies in a food processor until they reach a fine crumb consistency.
Transfer crumbs to a bowl and stir in the melted vegan butter until the mixture resembles wet sand.
Press the crumb mixture firmly into the bottom of a 20cm (8-inch) springform pan to create an even layer.
Place the crust in the refrigerator to chill for 30 minutes.
In a large mixing bowl, beat the vegan cream cheese using an electric mixer until smooth and aerated.
Add 200g of Biscoff spread, powdered sugar, and vanilla extract to the cream cheese and continue mixing until fully incorporated and thick.
Pour the cheesecake filling over the chilled crust and smooth the surface with an offset spatula.
Refrigerate the cheesecake for a minimum of 4 hours, or ideally overnight, until firm.
Melt the remaining 150g of Biscoff spread in the microwave for 20-30 seconds until liquid.
Pour the melted spread over the top of the chilled cheesecake, tilting the pan to ensure an even coating.
Garnish the edges with the 4 crushed cookies and chill for an additional 30 minutes before releasing from the springform pan and serving.