Layer the sponges evenly across the bottom of a deep glass serving bowl. Pour over the sherry and leave to soak for a few minutes.
Sprinkle over the raspberries in an even layer.
Make the custard according to the packet instructions and poor evenly over the sponge and raspberries. Put in the fridge for 15 minutes, or until the custard has set.
Meanwhile, whisk the cream with the sugar to soft peaks.
Once the custard is set, spoon over the cream and sprinkle with the toasted almonds.
Refrigerate for a few hours before serving, topping with the fresh raspberries at the last minute.