Preheat oven to 350 degrees F. Line a sheet pan with parchment paper and lightly butter it, set aside.
If hazelnuts are raw, toast them in the oven, and then rub the skins off in a clean, dry dishtowel. Blanch toasted hazelnuts in boiling water for 30 seconds and then immediately chill them in ice water. Squeeze the nuts through the skins.
Grind the hazelnuts in the bowl of a food processor fitted with a steel blade with 5 ounces confectioners' sugar, until smooth and fine, approximately 10 to 15 seconds.
Whisk together the hazelnut powder, 2 ounces confectioners' sugar, and flour lightly.
In a standing mixer, whip the egg whites on medium speed. When whites begin to foam, increase speed to high. When whites are at stiff peak, pour in the extra-fine sugar. Fold in dry ingredients in 3 additions.
Pour meringue mixture into piping bag without a tip. Pipe teardrop shapes with 2-inch diameter bottoms onto prepared sheet pan.
Bake for 7 to 8 minutes. Meringues will puff and begin to burst when finished baking. Meringues will be crispy on the outside but soft in the middle.
Serve immediately, or let cool and fill or top with ganache.
In a small sauce pan heat the heavy cream, vanilla bean, and Frangelico to a simmer. Place chocolate into a metal bowl. Once the cream simmers, remove the vanilla bean and pour it over the chocolate, stir until smooth. Let it cool to room temperature. With a rubber spatula, scrape ganache into a pastry bag fitted with a medium size star tip, and pipe into Hazelnut Meringues.
Frangelico Ganache recipe is courtesy of Food Network.