Preheat the oven to 190°C, fan 170°C, gas mark 5. Butter the bottom and sides of a 23cm springform tin. Line the sides of the tin with non-stick baking parchment.
Pulse the digestive biscuits and sugar together in a food processor until fine crumbs. Add the butter and pulse until mixed.
Press this evenly into the bottom of prepared tin and bake on a low shelf in the oven for about 15 minutes until golden brown and set. Transfer to a wire rack to cool for 10 minutes.
Using an electric food mixer (not food processor) or electric hand whisk, beat the lemon quark, butter and sugar until smooth.
Beat in the eggs and yolks one at a time until fully incorporated, then the lemon zest and vanilla extract.
Take a large piece of thick kitchen foil and place the lined tin in the centre. Wrap the foil tightly around the bottom and sides of the tin (this will prevent any water leaking into the biscuit base).
Set the foil-wrapped tin in a large roasting pan or deep oven tray and pour the cheesecake filling into the tin on top of the base. Smooth the top.
Pour boiling water from the kettle into the roasting pan so that it comes halfway up the sides of the cheesecake, and carefully transfer to the oven.
Bake for 1 hour until the top of the cheesecake is golden brown, the edges are set, and the centre is still slightly wobbly. Lift the cheesecake out of the water, drain well and remove the foil from the outside.
Cool completely, then chill in the refrigerator overnight or for at least 8 hours.
To serve, carefully remove the tin and baking parchment. Cut the cheesecake with a long, thin-bladed knife and serve slices with seasonal berries.
*All information included in this recipe has been provided by The Lake District Dairy Co.