Beat butter and cream cheese together until smooth with no streaks, about 2 minutes.

Add flour and salt, mix just until a soft dough forms.

Divide dough into 4 discs, wrap each in plastic, chill 1 hour until firm but still rollable.

Mix walnuts, sugar and cinnamon in a small bowl for the filling.

On a floured surface, roll one disc into a 9 inch circle.

Spread a thin layer of jam over the circle, then scatter a quarter of the nut filling evenly across it.

Cut the circle into 12 wedges with a pizza cutter.

Roll each wedge from the wide end to the point, curving the ends slightly to form a crescent.

Repeat with the remaining dough, placing cookies point-down on parchment-lined baking sheets, 1 inch apart.

Brush with beaten egg, sprinkle with coarse sugar, bake at 350°F for 18 to 20 minutes, until edges are golden and the jam bubbles at the seams.

Cool on the sheet 5 minutes before moving to a rack.