In a mixer, beat butter and cream cheese until light and fluffy. Add salt. Add flour, beating until it is absorbed.

Turn dough out onto a lightly floured piece of plastic wrap, form into a ball. Divide dough in half and press into a rectangle. Wrap each in plastic wrap tightly and refrigerate for about 2 hours. The dough may be frozen for up to 3 months, defrost in fridge overnight before using.

When ready to make and bake, preheat oven to 350°F. Line 2 sheet pans with parchment paper.

Make the filling. Combine sugar and cinnamon together in a small bowl.

Lightly flour the counter and work with one one batch of dough at a time, roll into a 8-inch x 12-inch rectangle.

Spread jam or butter over dough and sprinkle with cinnamon and sugar mixture leaving ½ inch border. Starting at one of the longer sides roll the dough up jelly roll style. Use a sharp knife or pizza cutter cut into 16 pieces and place seam side down on prepared pans. Refrigerate for at least 30 minutes or freezer for 15 minutes. You can also freeze them at this point to bake up fresh later. Cut frozen will keep shape better

Mix remaining cinnamon and sugar in a small bowl. Brush cookies with egg wash and sprinkle with cinnamon sugar. Bake until browned and flaky about 22 to 25 minutes.