In a large mixing bowl, cream together the softened butter and cream cheese until smooth. Gradually mix in sifted flour and salt until a cohesive dough forms.

Shape the dough into a flat disc, wrap it in plastic wrap, and refrigerate for 30 minutes.

Roll the chilled dough on a floured surface into a 10x30-inch rectangle.

Spread raspberry jam evenly over the dough, leaving a ½-inch border on one short edge. Roll the dough into a log, starting from the jam-covered side. Seal the log and refrigerate for 15 minutes.

Preheat oven to 375°F. Slice the log into ¼-inch thick rounds and place them on a parchment-lined baking sheet.

Bake for 17-20 minutes, or until edges are golden. Cool completely on a wire rack.

Dust with powdered sugar before serving.