Step 1

Stir water and 55g (1/4 cup) sugar in a heatproof bowl until sugar dissolves. Stir in lemon rind, juice and rum. Cool.

Step 2

Meanwhile, use an electric beater to beat cream, vanilla and remaining sugar in a bowl until firm peaks form. Beat in yoghurt until just combined.

Step 3

Divide lemon curd among glasses. Top with half the biscuit. Drizzle over half the syrup. Top with half the cream mixture. Repeat with remaining biscuit, syrup and cream mixture. Chill for 2 hours to develop the flavours. Top with raspberries and lemon zest.