| In large bowl mix 2 cups flour, undissolved yeast, sugar and salt.
Combine milk, chocolate chips, water and butter in small saucepan. Stir over medium-low heat until chocolate melts and temperature reaches 125? to 130?F. Gradually add to dry ingredients; blend well. Stir in enough remaining flour to make soft dough.
Knead dough on lightly floured surface 4 minutes or until smooth and elastic. Cover; let rest 10 minutes.
Prepare Chocolate Filling: In small bowl combine flour, sugar and unsweetened cocoa. With fork or pastry blender, cut in butter or margarine; blend well. Stir in egg yolks.
Divide dough into 10 pieces. Roll each piece into 4 ? 8-inch oval. Crumble about 3 tablespoons Chocolate Filling over each oval. Roll up from short end. Pinch seam to seal. Place rolls, seam side down, on greased baking sheets. With sharp knife, make 5 slits in top of each roll, cutting halfway through roll. Curve ends to make crescent shape.
Cover, let rise in warm place, free from draft until almost doubled in size, about 45 minutes. Bake at 375?F. 15 to 18 minutes or until done. Cool on wire rack. Top with sieved confectioners' sugar, if desired.