Preheat Oven: Preheat your oven to 160°C (320°F). Line a muffin tin with 8 cupcake liners.
Add the Biscoff biscuits to a food processor and blend for 10-30 seconds until fine crumbs form. Pour in the melted butter and process until a slightly sticky crumble forms.
Add 1.5 teaspoons of the base mixture to each cupcake liner. Press down firmly to form an even layer. Bake for 8-10 minutes, then let cool slightly.
In a large mixing bowl, combine the cream cheese, Greek yogurt, sweetener, egg, egg yolk, vanilla extract, and protein powder (if using). Whisk by hand or with an electric hand mixer until smooth and no clumps remain.
Spoon 2 tablespoons of the filling over each baked base, spreading evenly. Place the muffin tin in a water bath (optional but recommended) and bake for 20-25 minutes, or until the centers are just set.
Allow the cheesecakes to cool to room temperature, then refrigerate for a minimum of 3 hours or overnight for the best results.
Top each cheesecake with a dollop of light whipped cream and a strawberry to create the "Santa hat." Optionally, dust with icing sugar for an extra festive touch.