Preheat oven to 150°C.

First make the cranberry coulis: In medium heavy based saucepan, combine the water, cranberries, liqueur (if using), sugar and simmer for 10 minutes. Blitz and sieve out any seeds to give a purée. Add a squeeze of lemon juice if too sweet. Set aside to cool.

Crush the biscuits in a food processor until they resemble fine crumbs then stir in the melted butter until thoroughly moistened. Firmly press the biscuit crumb into the base of a well-greased 20cm springform cake tin until tightly packed and chill in the fridge for 10 mins.

Meanwhile, using an electric mixer, slowly whisk the ricotta and mascarpone together then add the sugar and vanilla extract. Next add one egg at a time until just blended and fold in the orange zest.

Pour the cheesecake filling into the chilled biscuit base and gently drizzle 2 tablespoons of cranberry coulis over the top from the outside inwards, then lightly swirl the coulis through the filling with a palette knife.

Place the cheesecake on a baking sheet and transfer to the centre of a preheated oven and bake at 150°C oven for 1 hour (the cheesecake should still wobble slightly in the centre). The next stage is to turn the oven off whilst leaving the cheesecake to cool inside the oven for at least 1 hour (it is a good idea to run a thin knife around the inner edge of the tin). Once you remove it from the oven leave in the tin at room temperature to cool fully before transferring to the fridge to chill completely.

To make topping. Place gelatine leaves in cold water for 10 minutes. Reheat the cranberry coulis, squeeze out any moisture and quickly stir the gelatine into the heated coulis, wait 1 minute for it to cool slightly before pouring it over the top of the cheesecake and return to the fridge to set.

When ready to serve, carefully remove from the tin and decorate with pomegranate seeds.