Preheat oven to 325°F (163°C). Prepare a 9-inch springform pan with parchment paper and grease the sides.
Mix crust ingredients and press firmly into the pan. Bake for 7–9 minutes, then let it cool.
Wrap the pan with foil to prepare for a water bath.
Reduce oven temperature to 300°F (148°C).
Beat cream cheese and Biscoff spread on low speed until smooth.
Add brown sugar and flour, then mix well.
Add sour cream and vanilla extract, mixing until combined.
Add eggs one at a time, mixing slowly after each addition.
Pour batter into crust and place in a water bath.
Bake for 1 hour 25 minutes until center is slightly jiggly.
Turn off oven and let cheesecake cool inside for 30 minutes, then slightly open the door for another 30 minutes.
Remove and refrigerate for 5–6 hours or overnight until fully set.
Warm Biscoff spread and pour over the cheesecake, then decorate with crumbs.