4 ounces gianduja (preferably Callebaut), chopped
5 large egg yolks
1/2 cup sugar
2 tablespoons Tia Maria or other coffee-flavored liqueur
1 teaspoon vanilla
4 ounces hazelnuts, toasted and coarsely chopped
2 cups well-chilled heavy cream
Raspberries, for garnish
chocolate sauce, for garnish