Preheat the oven to 180°C.
Cream the butter and sugar in a bowl until pale.
Beat in eggs individually, then fold in orange zest, juice, vanilla, and flour.
Pipe mixture into tins and bake for 15-20 minutes until golden.
Heat sugar and a tablespoon of water in a pan until dissolved.
Boil until the syrup reaches 160-175°C and cool base in water.
Dip hazelnuts on cocktail sticks into caramel and set on a tray.
Mix remaining hazelnuts into caramel, cool on parchment, and blend into powder.
Melt chocolate and butter together, then stir in the cream to make ganache.
Halve cooled cakes and fill with whipped cream.
Coat cakes in ganache and roll in the crushed hazelnut praline.
Pipe a mound of ganache on top and decorate with raspberries and caramel nuts.