Hazelnut Dacquoise

For the dacquoise

g/9oz blanched hazelnuts

g/10½oz caster sugar

g/1oz cornflour

large free-range egg whites

salt

For the chocolate ganache

g/5½oz plain chocolate, (around 35% cocoa solids), chopped

ml/3¾fl oz double cream

For the coffee custard filling

ml/20fl oz full-fat milk

large free-range egg yolks

g/4½oz caster sugar

Camp coffee essence

g/1¾oz cornflour

ml/10fl oz whipping cream

For the hazelnut praline

g/1¾oz caster sugar

whole blanched hazelnuts

lemon juice

For the decoration

g/3½oz roasted, chopped hazelnuts