In a medium bowl, using a hand mixer, cream the butter and cream cheese together until light and creamy. Add the flour slowly until the dough forms. Do not over-mix! Shape the dough into a ball and cover. Let the dough rest in the refrigerator for 30 minutes.
Preheat the oven to 375 degrees F.
On a lightly-floured surface, using a lightly-floured rolling pin, roll out the dough to 1/8-inch thickness. Using a 3-inch fluted biscuit cutter, cut out as many circles as you can. Form the scraps into a ball and reroll to make more circles.
Fill each dough circle with a small spoonful of the chocolate-hazelnut spread. Dip your finger in tap water and spread on the edge of half the circle to help create a seal. Fold the dough over to create a crescent. Bake until golden, about 15 minutes. Cool, then sift the confectioners' sugar on top and serve.