• Preheat oven to 325°. Grease a 9 inch springform pan with vegetable shortening and set aside. Fill a roasting pan (disposable would work) and place in oven on the lowest rack. This allows steam in the oven and will prevent the cheesecake from cracking.

Cookie butter crust

• In a food processor, pulse down the speculoos cookies to a fine cookie mixture dust. Put in a mixing bowl.
• Melt the ½ cup of butter in a microwavable bowl. Pour butter on the cookie mixture and add the granulated sugar and salt and mix until well combined. Press the mixture evenly into the bottom of the springform pan. Set aside.
  

Cheesecake filling

• In a large bowl, beat the cream cheese until smooth on medium speed. Add sugar and salt and beat until thoroughly combined.
  
• Turn down speed to low and add eggs one at a time. Mixing until all the eggs are combined.
  
• Add in the whipping cream, sour cream and vanilla extract. Beat until incorporated, scraping down the sides of the bowl as needed.
  
• Gently fold in cookie butter and then pour filling over prepared crust. Place in roaster pan.
  
• Bake the cheesecake until the edges are firm and the center is still jiggly about 1 hour and 15 minutes. Let it cool to room temperature. Once cool, cover with aluminum foil and refrigerate overnight.
  
• To serve, garnish with crushed biscoff cookies and drizzle with melted cookie butter.