Line a loaf pan with plastic wrap (cling film) or aluminum foil. In a medium saucepan, warm the cream without allowing it to come to a boil.
Break the dark and light chocolate into small pieces then add it along with the coconut fat to the saucepan with the cream. Combine and allow the chocolate and coconut fat to melt under medium to low heat, stirring constantly until entirely melted.
Add the vanilla sugar then stir to combine. Remove from the heat and set aside.
Use a spatula or a spoon to evenly spread a thin layer of the chocolate ganache on the prepared loaf pan, then top with the biscuits, without having the biscuits touch the sides of the loaf pan, if possible.
Repeat the process, alternating between the chocolate and the biscuits, until all the ingredients have been used up.
Once done, cover with plastic wrap and refrigerate for 3-5 hours (or overnight) to enable the cake to set.
To serve, carefully flip the cake to a plate and peel off the plastic wrap or aluminum foil. Cut into slices and enjoy!
Notes
To make this cake extra special for the Christmas holidays, use Spekulatius (or biscoff) biscuits.
Kalter Hund tastes best when served cold. For this reason, keep it in the fridge and only remove it when ready to serve.
Use a sharp knife when serving, to prevent the biscuit pieces from breaking up.
Nutritional information is an estimate for 1 serving using the ingredients listed (excluding the optional ones), calculated using tools we use. Actual macros may vary slightly depending on specific brands and specific ingredients you use. The total time excludes the time it takes to set the Kalter Hund in the fridge.