Stir together flour, baking powder and salt in a medium bowl; set aside.
Combine Nutella and shortening in a large mixing bowl; beat with electric mixer
on medium to high speed until combined. Add sugar; beat on medium speed until fluffy.
Add vanilla extract and eggs; beat just until combined.
Alternately add flour mixture and milk to creamed mixture, beating on medium
speed just until combined. Use a spoon to stir in 1/2 cup chopped hazelnuts. Cover
and chill for several hours or until firm.
Heat oven to 375 degrees F.
Shape the dough into 1- or 1 1/2-inch balls. Roll the balls in finely chopped
hazelnuts, then roll in confectioners' sugar. Place the balls 2 inches apart
on a lightly greased cookie sheet. (The cookies will spread and crinkle as they bake.)
Bake for 8 to 10 minutes or until surface is cracked and cookies are set.