Cup of Yum
1. In a mixing bowl beat the butter and sifted sugar until you get a pale and fluffy cream.
2. Add the yolk (if using) and incorporate it well into the mixture.
3. Add the whey-free cream gradually until you get a homogeneous mixture and reserve.
4. Add 1 tablespoon of port wine or liquor, if using mix well and set aside while we prepare the base.

For the cookie base:

1. Prepare a deep dish with milk and a springform cake pan.
2. Dip the cornstarch biscuits in the milk and arrange them in a layer at the bottom of the pan. You can also place some along the edge to form an upward crust.
3. Divide the cream in 3 parts and spread 1/3 of it into an even layer. Follow with another layer of moistened biscuits and the next third of the cream, alternating in this way until you finish with a final layer of biscuits.
4. Cover the pan with plastic film and place in the fridge until firm (at least 5 hours or overnight would be best).

For the chocolate ganache:

1. Once set, it's time to prepare the chocolate topping. To do this, heat up the heavy cream in a saucepan on medium-low heat until it begins to bubble. Remove from the heat and stir in the chocolate powder, and butter and continue stirring until it thickens. Set aside to cool.
2. Pour the chocolate ganache over the cake and serve cold.

Enjoy!