(*) Chocolate hazelnut paste can be found in gourmet stores and supermarkets in the jam section. Nutella is a well-known brand. Kosher brands are available.
Cream the sugar with the butter (or margarine) and cream cheese. Blend in the flour, baking powder, cocoa powder, salt, vanilla and chocolate extracts. Stir to make a soft dough, adding a little flour as necessary if dough is too sticky. Turn dough out onto a lightly floured board and pat into a flattened discup Wrap in plastic and chill for 30-60 minutes or overnight.
Stack two baking sheets together and line the top one with parchment paper. To prepare the pastries, remove dough from fridge. Have filling ingredients nearby. Preheat the oven to 350 F. Whisk the egg with sugar in a small bowl. On a lightly floured work surface, roll out a portion at a time into a circle of about 10 inch diameter. Using a pastry wheel, cut the portion of dough into 10-12 wedges.
Smear on some hazelnut paste, sugar and chocolate chips. Roll each pastry, from the outer edge into the center, into a small, snug crescent. Using a pastry brush, brush pastries with egg wash.
Place pastries, about 2 inches apart, on prepared baking sheet. Repeat with remaining dough. Bake on middle rack of oven, until nicely golden brown, about 25-32 minutes.
Makes about 30 pastries. Once cooled, you can also dust these with powdered sugar or drizzle with melted chocolate.