Step 1

Process biscuits until mixture resembles fine breadcrumbs. Add butter; process until just combined.

Step 2

Using one hand, press crumb mixture evenly over base of greased 21cm springform tin.

Step 3

Cover; refrigerate 30 minutes or until firm.

Step 4

For filling, beat cheese, sugar, essence and creme de cacao in large bowl with electric mixer until smooth and fluffy. Add peel and chocolate; mix well.

Step 5

Spoon filling over biscuit base; refrigerate at least 6 hours or overnight.

Step 6

Serve cream spooned onto wedges of cake. Sprinkle with chocolate.