Cream butter and cream cheese in stand mixer with a paddle attachment until creamy. Add sugar, salt and vanilla. Mix well.
Add flour and mix until just combined. Dump the dough onto a well floured surface and roll into a ball. Cut the ball in quarters and wrap each quarter in plastic wrap. Refrigerate for at least 30 minutes or in the freezer for 15 minutes.
For the filling: In 1 bowl, mix together the brown sugar, granulated sugar, cinnamon, nutmeg and pistachios. In another bowl, stir together the black cherry preserves and orange zest.
Take one dough-ball out of fridge (leaving others chilled until ready to use) and on a well-floured surface, roll it out using a floured rolling pin. Roll it out to about 9 inches in diameter.
*It will feel somewhat hard/stiff in the very beginning, but this is such a beautiful soft dough, once you start working it, it gets easier.
If you have a round cheese cake pan or any 9-10in pan, use that as a guide to cut a perfect circle for your rolled out dough and save the excess cut-outs to use again.
Take 2 Tb of preserves and spread a thin layer on the dough. Less is more in this case.
Now take 1/4 c of pistachio mixture and spread it evenly on the preserves, lightly pressing down.
Using a very sharp knife or even a pizza cutter, but the dough in half, then in quarters.
Then cut the quarters in half.
Now here's where to be gentle and take your time! Take one of the wedges and roll from the outside-in.
Once all of them are rolled up, place them on cookie sheet, end-side down and brush with egg wash and sprinkle with cinnamon sugar.
Bake at 350 degrees Fahrenheit for about 15-18 minutes until lightly golden brown.