Cut the cold butter and cream cheese into 12 small cubes each. 

Pulse in a food processor with the flour and salt until it starts to clump together, forming curds. Don't process long enough for it to gather into a ball.

Divide the dough into two equal pieces and flatten into six-inch disks. Cover with plastic wrap and refrigerate for two hours or overnight.

Stir the apricot jam until spreadable. Squish any large chunks.

Combine the roasted walnuts, brown sugar, cinnamon, and orange zest in a bowl. 

Whisk the egg in a bowl.

Combine the sugar and walnuts in a bowl.

Remove the pastry from the refrigerator and remove plastic.

On a lightly floured surface, roll each disk out into a 10 to 11-inch circle.

Brush half of the apricot jam over each circle, then sprinkle half of the walnut, brown sugar, and cinnamon mixture over the jam on each circle.

Using a sharp knife or a pizza cutter, cut the circles into 12 triangles each. (Cut the circle into fourths and each fourth into 3 pieces.)

Roll each triangle up into a crescent, starting at the wide end.

Place on a parchment lined baking sheet.

Brush each Rugelach with beaten egg, then sprinkle on the walnut and sugar mixture.

Bake in a 350 degree F oven until golden and beginning to caramelize, about 25-30 minutes.

Remove from oven and cool on a rack.

Best eaten the day they are made. However, they can be stored in a closed container at room temperature for several days.