1-Whip the heavy cream: Whip the heavy cream. Pour 2 cups heavy cream in the bowl of a stand mixer fitted with whisk attachment. Whisk until medium peaks form.
2-Add cookie butter: Add cookie butter. Add ½ cup (150g) Biscoff, ⅓ cup (80g) mascarpone cream, and 1 tsp pure vanilla extract, a pinch of Kosher salt, and 2 Tbsp confectioner’s sugar, then incorporate until well mixed.
3-Assemble the icebox cake: Assemble the icebox cake. Line the loaf pan with a piece of plastic wrap, then place a single layer of Biscoff cookies along the bottom. Spread a layer of the Biscoff cream mixture on top of the cookies so that it’s roughly the same thickness as the cookie layer. Repeat until you reach the top, ending with a layer of cookies.
4-Refrigerate for 24 hours: Refrigerate for 24 hours. Loosely wrap the loaf pan with plastic wrap, then refrigerate for 24 hours. When ready to serve, unmold onto a plate or tray. Serve with a drizzle of warmed Biscoff spread and crushed Biscoff cookies.