These were the hit of my last Chocothon. I've tried them with bittersweet chocolate, but I like them better with milk, and I'm usually a huge bittersweet snob.
~ 1 1/2 lbs. milk chocolate
8 oz. hazelnut butter
1 cup chopped roasted hazelnuts (skins mostly removed)
Temper 8 oz. of milk chocolate. Stir in the hazelnut butter until thoroughly combined, then the chopped hazelnuts. Cover and allow to set until firm; this will take about 12 hours. Roll the mixture into 1/2 - 3/4 inch balls, and allow them to sit to firm up a bit. Temper about 1 pound of milk chocolate. Dip the balls of hazelnut filling into the tempered chocolate, drop them onto paper (I use baking parchment; waxed paper or even copier paper is okay.), and allow to set. The texture will be best the next day.