White Chocolate Lime and Coconut Cheesecake

Preheat the oven to 160°C. 

Grease a 23cm removable-base cake tin and line the base and sides with baking paper.

Base: Whizz the biscuits, butter, coconut and lime zest together in a food processor until the mixture has the texture of damp sand, then pour into the prepared tin. Squash the biscuit crumbs into the base and halfway up the sides of the tin, using the base of a glass to press the sides firmly, and a tablespoon to compact the base. Pop the base in the fridge while you make the filling.

Filling: Melt the white chocolate either in a heatproof bowl over a saucepan of simmering water (don’t let the base of the bowl touch the water), or in 30-second bursts at 70 per cent power in the microwave, stirring in between. Whisk until smooth. 

While the chocolate is melting, wipe out the food processor and put in the cream cheese (chopped into big chunks), sour cream, caster sugar, eggs and yolks and whizz until smooth. 
Mix the custard powder and lime juice to a smooth paste and add to the cream cheese with the zest. Briefly whizz again to incorporate. With the motor running, add the melted white chocolate in a couple of lots until well incorporated.

Pour the filling into the chilled base. Cook for 60–65 minutes, reducing the oven temperature to 150°C for the last 5-10 minutes. The cheesecake is ready once it is fully set, but with a bit of wobble still in the middle. Turn the oven off and open the oven door a little then allow the cheesecake to cool in the oven to avoid surface cracking. Once cold, refrigerate until an hour before serving.

Topping: Line an oven tray with baking paper. Put the caster sugar in a large deep frying pan with 1 cup water, bring to a simmer and whisk to dissolve the sugar. Simmer for 5 minutes until becoming syrupy then add the lime rounds. Cook for 10 minutes, turning once halfway through. Put the rounds on the baking paper to cool, then cover with another sheet of baking paper. These can be stored in the fridge up to a day before using.

Beat the cream to soft peaks in a large bowl. Add the sour cream and continue beating to combine. Add the icing sugar and beat again until medium firm peaks. An hour before serving pile the cream onto the cheesecake and refrigerate for half an hour to firm up. It can then be removed from the fridge to serve, decorated as desired with lime rounds, coconut shavings, fresh berries and edible flowers.