Melt the butter and crush the digestives. Mix together until everything is well coated and then pour into a small springform pan (mine was 18cm / 6in). Push down into the bottom of the pan with the back of a spoon until you have a fairly even coverage. Pop in the fridge while you make the filling.

Melt the white chocolate for the filling and leave to cool. In the meantime, beat the cream cheese, Greek yoghurt and vanilla sugar together using an electric whisk. Add enough food colouring until the desired colour is reached (if using), then finally, the cooled chocolate and whisk again just until everything is combined. Pour over the crust and smooth off the top. Leave in the fridge for several hours (I left mine overnight).

For the chocolate ganache: heat the cream in a small pan just until it starts a slow, rolling boil. In the meantime, chop or break up the chocolate into small pieces and put in a medium sized bowl. When ready, pour the cream over the chocolate (so that it is all covered) and leave for five minutes (don't be tempted to stir before that). After the allotted time, the cream and chocolate will have transformed into thick, shiny ganache.

Pour over the hardened filling and using a small palette or frosting knife, smooth the chocolate into place. Leave to set for around 30 minutes before attaching any decorations, then place in the fridge to completely set for several hours.

Pop into the freezer for around and hour before serving, just to make it a little easier to slice (the middle will still be squidgy, especially when you try to cut through the hardened ganache). Keep in the fridge until you are ready to eat it. Enjoy!