Crush the cookies and mix with the melted butter. Line a 9-inch (22 cm) springform pan with parchment paper. Press the mixture firmly into the bottom to form the crust, then refrigerate for 30 minutes.

In a bowl, combine the mascarpone, cream cheese, powdered sugar, and Biscoff spread. Mix well. Whip the heavy cream and gently fold it into the mixture.

Chop the dark chocolate and fold it in until well combined.

Soak the gelatin in cold water for 10 minutes. After soaking, squeeze out the excess water and heat it with 2 tablespoons of milk just until dissolved.

Heat the cream, then carefully add it to the caramelized sugar and stir well. Add the salt, then the butter. Be careful during this step. Stir until smooth and creamy.

If you need to transport the cake, I recommend placing it in the freezer so the salted caramel sets; otherwise, the caramel may run off. Alternatively, you can add the salted caramel as a decoration after slicing.

I do not recommend adding gelatin to the caramel topping, as it takes away from the classic salted flavor.