Preparation time 30 mins to 1 hour, Cooking time less than 10 mins.
Make the cheesecake base:
Melt the butter in a small saucepan on a low heat. Crush the cookies in a bag using a rolling pin to a medium to fine crumb. Mix the butter with the cookie crumbs ensuring the crumbs are well coated. Place a spring sided 20cm/8in ring mould or 6 individual shaped moulds of choice on a lined flat baking tray. Spoon the buttered crumbs into the mould(s) to form a base and place in the refrigerator to chill.
Make the cheesecake filling:
Place the egg yolks in a medium sized mixing bowl, add the sugar and using a hand whisk or electric whisk, mix to make a sabayon. The mixture should be at a thick ribbon stage to nearly hold its own shape, light coloured and smooth in texture. In a separate bowl beat the cheese until just softened and smooth. Whisk into the egg mixture then add the Carolans Irish Cream and mix until soft.
In a shallow dish, cover the gelatine with hot water. Leave to soak for a few minutes until softened, then drain and put into a pan with 2 tbsp /30ml/1fl oz of water. Heat gently, swirling until dissolved.
Cool, then whisk into the cheese mixture. Fold in the zest. Whip the double cream to soft peaks and fold in. Pour the mixture on top of the base in the tin and chill for at least 1½ hour.