Prepare the pan by wrapping a 9-inch springform pan with aluminum foil and placing it inside a larger baking dish. Preheat your oven to 350°F.

In a mixing bowl, combine streusel ingredients and blend until it resembles coarse crumbs. Chill while preparing the crust.

Blend Biscoff cookies, granulated sugar, and melted butter in a food processor to a sandy texture. Press into the prepared springform pan and bake for 15 minutes.

In a mixing bowl, beat softened cream cheese, then add sugar and cornstarch. Fold in pumpkin purée, sour cream, spices, and vanilla. Incorporate eggs gently.

Pour half of filling over the crust, add half of the streusel, then remaining filling and streusel. Bake in the water bath for 1.5 hours.

After baking, turn off the oven and leave the cheesecake inside for 1 hour to cool gradually. Then refrigerate for at least 8 hours.

Before serving, whip heavy cream with powdered sugar until stiff peaks form. Pipe around edges and garnish with Biscoff cookie crumbs.