Preheat the Oven and Prepare the Pan

1. Preheat your oven to 375°F (190°C). Line a standard muffin pan with 12 muffin liners. Set the pan aside for later.

Make the Crust

2. In the bowl of a food processor, add the Biscoff cookies and light brown sugar. Pulse until the cookies turn into fine crumbs, with no large chunks remaining.
3. Add the melted butter and pulse again until the mixture combines, and the crumbs begin to stick together.
4. Divide the crust mixture evenly among the 12 muffin liners. Press the crumbs down firmly using the back of a spoon to form a solid crust.
5. Bake the crusts in the preheated oven for 5 minutes, then remove the pan and lower the oven temperature to 325°F (165°C). Let the crusts cool while you prepare the cheesecake filling.

Make the Cheesecake

6. In a large mixing bowl, beat together the cream cheese, cookie butter, granulated sugar, sour cream, heavy cream, vanilla extract, and salt using an electric hand mixer on medium speed until smooth and creamy.
7. Add the egg and egg yolk, and beat on low speed just until combined—be careful not to overmix.
8. Spoon the cheesecake mixture onto the crusts, filling each muffin liner nearly to the top (about 3 tablespoons of cheesecake per liner). You may have a little cheesecake batter left over, which can be used to fill more liners or baked into mini cheesecakes later.
9. Return the pan to the oven and bake for 15 minutes, or until the edges of each cheesecake are set but the centers still wobble slightly when you jiggle the pan.
10. Turn off the oven and leave the cheesecakes inside with the door closed for 10 minutes. Then, crack the oven door open and let the cheesecakes sit for another 10 minutes.
11. Transfer the pan to a wire rack and let the cheesecakes cool completely (about 1 hour). Afterward, place the pan in the fridge and chill the cheesecakes for at least 2 hours, or up to overnight.

Garnish the Cheesecakes

12. Once the cheesecakes are chilled and set, heat the Biscoff cookie butter topping in the microwave at 50% power until it becomes pourable, about 20-30 seconds.
13. Spoon or drizzle 1 teaspoon of the warmed cookie butter onto each cheesecake.
14. Return the cheesecakes to the fridge for 30 minutes to allow the topping to solidify.
15. Let the cheesecakes rest at room temperature for 5-10 minutes before serving.