1. Preheat oven to 180°C fan (190°C conventional). Blitz the biscuits in a food processor to a fine crumb. Melt the butter and stir through the biscuit crumb with a knife until it resembles wet sand. Into the base of a well greased 20cm (8inch) springform cake tin, first use the back of a teaspoon to spread out and level the crumbs, firmly press with your hands until tightly packed, chill in the fridge for 10 mins to harden the base.

2. Meanwhile, using an electric mixer, slowly whisk the cream cheese, sour cream and caster sugar until lump free. Next add one egg at a time until smooth, followed by the vanilla extract and Irish Cream liqueur.

3. Pour the mixture over the chilled biscuit base and bake in the preheated oven for 35-40 minutes. Normally, after 35 minutes, the cheesecake will still have a slight wobble in the centre, but turn the oven off while leaving the cheesecake to cool inside the oven for 1 hour (resist the urge to open and close the door).

4. Remove from the oven and run a thin knife around the inner edge so the sides don’t stick to the tin as it shrinks away from the tin walls. Allow to cook at room temperature fully before covering with clingfilm and transferring to the fridge.

5. When ready to serve, remove from the tin, and decorate with whipped cream, fresh raspberries and flake.

Variation: Digestive biscuits provide an alternative yet classic biscuit base or you can combine them with half and half amaretti biscuits, Oreos or hob nobs. Chopped hazelnuts add a good crunch.