slice cold butter and cream cheese into smaller pieces. Put all into your food processor along with the sour cream, flour, salt, and sugar. Pulse together until a crumbly dough starts to form and begins to fall away from the sides of the processor. Don't over process; the dough should be crumbly but will hold together in your hand,
Form the dough into a ball. Divide the ball into four equal pieces and form each of those pieces into balls. Cover with plastic and place in the refrigerator for at least an hour up to 48 hours.
You can use a mixer instead of a food processor, just bring the butter and cream cheese to room temperature and cream them together before adding the dry ingredients.
While the dough is resting - In a skillet, toast the chopped nuts over medium heat until fragrant. Pour the toasted nuts into the food processor along with the chocolate chips, berry preserves, and brown sugar. Pulse together until a thick, coarse paste forms. set aside.
Combine the cinnamon and sugar in a small bowl; reserve. Beat your egg wash with water. set aside.
Preheat oven to 375 degrees F. Lightly flour your rolling surface and rolling pin. Take one portion of the dough out the refrigerator (keep the rest of the dough cold until ready to use). Roll out the dough to about 1/8 inch thickness. The dough while hard to press initially it will become more pliable as it starts to warm.
Lift the dough gently from the rolling surface (it may stick a bit) and re-flour your surface beneath the dough. you can free hand cut a 9 inch circle or take a cake pan and make an indent. Then trace around it with a knife. Place the excess dough into the fridge under the plastic for your fifth batch.
Take about 4 tbsp of the filling and place it in the center of the circle. Spread it very thin across the surface of the dough; leaving about an inch around the outer edge of the dough empty, Too much filling will make your cookie expand too much.
Cut the circle into 8 equal triangles by first cutting the circle in half...then quarters...then halve the quarters to make eighths. If you prefer to make smaller bite-sized cookies, divide each quarter into three to make 12 equal triangles.
Roll each triangle, starting from the wide flat end and rolling towards the narrow point to form a crescent roll shape. Place; end point down onto your prepared cookie sheet. Either use a Silpat or parchment paper. They do expand a bit so leave about an inch in between each cookie.
When you are ready to bake, brush the top of each cookie with egg wash, then sprinkle lightly with cinnamon sugar.
Place cookies in the oven and let them back for about 20 minutes, or until golden brown. Once removed from the oven let them cool on a wire rack. Serve warm from the oven or store for a few days in an airtight container,