Place flour and salt in the bowl of a food processor and pulse to combine. Add butter, and pulse 10 times. Pulse in cream cheese until the mixture becomes crumbly. Sprinkle in buttermilk and pulse until the mixture comes together when pressed. Transfer the dough to a work surface, and divide into thirds. Wrap each third in plastic, and shape into a disc. Refrigerate discs for at least 3 hours, or overnight.
Combine sugar, cinnamon, chopped walnuts, and finely chopped raisins (may substitute miniature chocolate chips for raisins).
Roll each disk into a 9 inch round keeping other disks chilled until ready to roll them. Sprinkle round with sugar/nut mixture. Press lightly into dough. With chefs knife or pizza cutter, cut each round into 12 wedges. Roll wedges from wide to narrow, you will end up with point on outside of cookie. Place on ungreased baking sheets and chill rugelach 20 minutes before baking.
Preheat the oven to 350 degrees. Line a baking sheet with a Silpat baking mat or parchment paper.
Bake until golden brown, 18 to 22 minutes. Transfer to a wire rack to cool, and store in an airtight container. Repeat with remaining 2/3 of dough.