Heat oven to 425°F. Line cookie sheet with cooking parchment paper. Remove pie crust from pouch; unroll on work surface. Brush both sides of crust with melted butter.
In small bowl, mix granulated sugar and cinnamon. Sprinkle over one side of pie crust; press gently. Cut into fourths. Place sugar side down on parchment-lined cookie sheet.
Spread 1 1/2 teaspoons cream cheese down center of each crust piece. Gently spread 1 teaspoon hazelnut spread over cream cheese on each. Fold each triangle in half, and press slightly to seal. Sprinkle tops with chopped hazelnuts; press gently into crust.
Bake 10 to 14 minutes or until golden brown. Remove immediately to cooling rack; cool 5 minutes.
Meanwhile, in small bowl, mix powdered sugar and enough milk for desired drizzling consistency until smooth. Drizzle over triangles.