Ingredients

• 1.5kg/3lb 5oz rhubarb
• trimmed
• 175g/6oz caster sugar
• 300g/10½oz stem ginger biscuits
• 115g/4oz unsalted butter
• melted
• 450g/1lb full-fat cream cheese
• 2 lemons
• zest only
• 300ml/½ pint soured cream
• 6 free-range eggs
• separated
• 1 tbsp icing sugar

Directions

• Preheat the oven to 200C/400F/Gas 6. Grease and line a 25cm/10in loose-bottomed cake tin.
• Cut two thirds of the rhubarb into pieces about 5cm/2in long
• place in an ovenproof dish and sprinkle with 55g/2oz of the caster sugar. Roast in the oven for 20 minutes or until tender.
• Meanwhile
• cut the remaining rhubarb into pieces about 7.5cm/3in long
• place in another ovenproof dish with a tablespoon of the caster sugar and roast until just tender but still holding their shape. Set aside to decorate the cheesecake.
• To make the biscuit base
• place the stem ginger biscuits in a plastic bag and crush with a rolling pin
• leaving the mixture quite rough. Place the biscuit crumbs in a bowl
• mix in the melted butter and press into the bottom of the prepared cake tin. Place in the fridge while you make the cheesecake mixture.
• Beat the cream cheese with the remaining 125g/4½oz caster sugar and the lemon zest
• then add the soured cream and egg yolks and beat until smooth.
• Spread the rhubarb onto the chilled biscuit base. Whisk the egg whites until they hold soft peaks then fold into the cheese mixture and pour on top of the rhubarb.
• Bake in the oven for about one hour
• reducing the heat to 180C/350F/Gas 4 once the cheesecake has risen. The top should be firm to the touch but still slightly wobbly. Let the cheesecake to cool then remove it from the tin
• arrange the reserved rhubarb on top and dust with the icing sugar.