In a mixing bowl, combine the flour and salt.

Add the softened butter and cream cheese to the flour mixture. Blend until smooth, forming a soft dough.

Wrap the dough in plastic wrap and refrigerate for at least one hour.

In a small bowl, mix together chocolate chips, chopped nuts, brown sugar, and cinnamon.

On a floured surface, divide the chilled dough into quarters. Roll out one quarter into a thin circle, about 1/8-inch thick.

Evenly spread a portion of the filling mixture over the rolled-out dough.

Using a sharp knife or pizza cutter, cut the dough into wedges and roll each wedge tightly.

Place the rolled rugelach on a baking sheet lined with parchment paper. Brush with the beaten egg and bake at 350°F (175°C) for about 25 minutes.

Let the rugelach cool completely on a wire rack before serving.