- Mix the crushed digestive biscuits with the melted butter, press into the base of a 20cm springform tin using the back of a spoon. Refrigerate for 30 minutes.
- Preheat the oven to 180C and cover the base and outside of the tin with foil. Fold some foil to make strips and lay them to make a cross shape. Place the tin on top of the cross and bring the four strips up the sides of the tin, so that it can be lifted out of the roasting tin (baine marie/water bath) when cooked. Prepare some boiling water to pour in a medium size roasting tin.
- In a large bowl whisk the egg yolks and eggs until combined. Beat in the cream cheese, cream, sugar, orange zest and liqueur. Beat until only just combined and pour over the chilled cheesecake base.
- Put the tin into the roasting tin and pour in some boiling water, about 2cm up the side of the tin. Bake the cheesecake for 1hour 20mins - 1hour 40mins. As soon as the cheesecake comes out the oven place the grated chocolate on top and leave to cool in the water bath for a further 15 minutes.
- Take the cheesecake out of the water bath and leave to cool for another hour. Cover with clingfilm and leave in the fridge, overnight if possible. When serving place chocolate orange segments around the side. Enjoy!