Make the pastry. In a food processor, mix the flour, salt, and brown sugar. Add the cream cheese, butter, sour cream, and vanilla and pulse just until the mixture begins to form a ball around the blades. Do not overprocess. Transfer the dough to a work surface and knead lightly and quickly into a smooth, compact roll. (Or prepare manually: In a large bowl, quickly mix together the cream cheese, butter, sour cream, and vanilla until well blended. Gradually add the flour, salt, and sugar. Knead the mixture lightly until thoroughly combined and smooth.).
Divide the dough into 4 equal parts. Put each piece between two sheets of wax paper and flatten into a large oblong using the palm of your hand. If necessary, refrigerate briefly until the dough is firm enough to roll.
Work with one oblong at a time, keeping the others refrigerated. Roll the oblong between the wax paper into a 12-by-7-inch rectangle, about 1/8 inch thick. Leaving the dough in the wax paper, refrigerate for at least 4 hours or up to 2 days. Repeat with the other 3 rectangles.
Loosen the wax paper from both sides of the dough. (The paper becomes pressed into the dough with rolling and will be difficult to remove after you cut the dough unless it has been loosened first.) Place the dough rectangle back down on a sheet of the wax paper, and sprinkle it all over with 2 table-spoons brown sugar. Now cut the rectangle in half. You should have two 6-by-7-inch sections. Cut each section into 4 equal strips, giving you 8 in all. Leaving a 1/2 inch border, place some caramel pieces and pecans over each dough strip (be generousâ€”the more caramels, the more luscious the taste). If your caramels are soft enough, press the pieces with your fingertips to flatten them. You'll get a smoother, tighter roll. Roll each strip up tightly, jelly-roll fashion, and place seam side down, about I inch apart, on a baking sheet lined with parchment. (If the dough becomes too soft to work with during the rolling or filling, place it on a lined cookie sheet in the freezer until firm again.) Refrigerate the prepared rugelach while you make rugelach with the rest of the dough. The prepared rugelach should be refrigerated for at least 30 minutes before you bake them.
Preheat the oven to 375°F Bake in the middle of the oven for about 20 minutes, or until pale golden. If necessary, adjust the pans during baking so the rugelach cook evenly. Transfer the pan to a rack and let the rugelach cool completely. Remove the rugelach carefully with a thin-bladed spatula. Store the rugelach in airtight containers for up to 4 days.