Ingredients

• 50g/2oz unsalted butter
• 150g/5½oz digestive biscuits, crushed to fine crumbs
• 350g/12oz full-fat cream cheese
• 150g/5½oz golden caster sugar
• 4 medium eggs
• 2 lemons, finely grated zest and juice
• 1 tsp vanilla extract
• 300ml/½pt sour cream

Method

1. Preheat the oven to 190C/375F/gas mark 5.
2. Gently melt the butter in a small pan over a low heat.
3. Place the digestive biscuits in a plastic bag and crush them to fine crumbs using a rolling pin. Tip them into the pan with the melted butter and stir to coat them, then transfer to a 20cm/8in cake tin with a removable base. Using your fingers or the bottom of a tumbler, press them into the base.
4. Place all the ingredients for the filling except the sour cream in the bowl of a food processor and whiz until smooth.
5. Carefully pour the mixture on top of the biscuit-crumb base (use the back of a spoon as a chute to avoid disturbing the crumbs).
6. Bake the cheesecake for 30 minutes until it is just set and slightly risen (it may also be starting to colour).
7. Remove and leave it for 5-10 minutes for the surface to level, then smooth the sour cream over the surface and return to the oven for 10 minutes. It may still appear slightly shiny and liquid, but will firm up on cooling and chilling.
8. Remove and leave the cheesecake to cool, then cover it with clingfilm and chill overnight. Serve the cheesecake chilled.

Notes