A departing colleague brought this into work for her last morning tea with us - it was so decadently divine she was banned from leaving until she'd shared her recipe!
Line a greased springform pan with the mixture. Refrigerate at least 30 minutes.
Beat sugar and cream cheese.
Add 1 cup of cream, stir through.
Add marscarpone, stir through.
Melt white chocolate in metal bowl over simmering water. Stir melted chocolate through mixture.
Spoon onto base and smooth. Refrigerate at least 3 hours.
To make dark chocolate sauce (optional but truly decadent!) - melt dark chocolate in metal bowl over simmering water. Stir through remaining 3/4 cup cream.
Slice cake to serve, spoon chocolate sauce over the top of each portion.