Chocolate charlotte

Grease and line the base of a 24cm (base diameter) round springform pan with baking paper. Place liqueur in a shallow bowl. Cut 2cm off one end of each biscuit. Working quickly, dip biscuits, one by one, into liqueur (don't let them soak). Line side of prepared pan with dipped biscuits, cut-end touching base of pan and curved surface facing outwards. Line base of pan with dipped biscuits; cutting to fit so that base is completely covered.

Place chocolate and milk in a medium heatproof bowl over a saucepan of simmering water (don't let base of bowl touch water). Stir until melted and smooth. Add butter, piece by piece, stirring after each addition, until melted and smooth. Remove bowl from pan; cool slightly. Add egg yolks; beat mixture with a wooden spoon until smooth and glossy. Cool completely.

Using an electric mixer, beat cream in a large bowl until soft peaks form. Fold chocolate mixture into cream. Using an electric mixer, beat egg whites in a medium clean dry bowl until soft peaks form. Add sugar; beat for 2 minutes or until thick and glossy. Fold a third of the egg white mixture into chocolate mixture until well combined, then fold in remaining egg white mixture until just combined. Pour into prepared pan. Smooth surface. Cover with plastic food wrap; refrigerate overnight or until firm. Remove Charlotte from pan. Serve sprinkled with extra shaved chocolate and blueberries