Polish Apricot-Filled Cookies

Whisk together flour and salt in a bowl until combined.
Beat cream cheese and butter in a large bowl with an electric mixer at medium-high speed until pale and creamy, about 3 minutes in a stand mixer (preferably fitted with a paddle attachment) or 6 minutes with a handheld. Reduce mixer speed to low, then add flour mixture and mix just until combined.
Divide dough into 4 equal pieces and wrap each in plastic wrap. Chill until firm, about 1 1/2 hours.
Bring apricots, raisins, honey, marmalade, cinnamon and water to a boil in a 2- to 3-quart heavy saucepan over moderate heat, stirring. Reduce heat and simmer, stirring, until dried fruit is softened and mixture is thick, about 10 minutes. Transfer to a small bowl and cool until warm, about 20 minutes. Transfer to a food processor and pulse until finely chopped. Chill until cold, about 2 hours.
Put oven rack in middle position and preheat oven to 375°F. Line a large baking sheet with parchment.
Roll out 1 piece of dough (keep remaining pieces chilled) between 2 (12-inch) sheets of well-floured wax paper with a rolling pin into a roughly 11-inch square. (If dough gets too soft, transfer dough in wax paper to a baking sheet and chill until firm.) Discard top sheet of wax paper and trim dough with a pastry wheel or sharp knife into a 10-inch square. Cut square into 4 equal strips, then cut crosswise in fourths again to form a total of 16 (2 1/2-inch) squares.
Working quickly, place 1 heaping teaspoon filling in center of each square. Brush 2 opposite corners with egg wash, then bring corners together and pinch firmly to adhere. (If dough becomes too soft, freeze it on a baking sheet for a few minutes.)
Arrange cookies 2 inches apart on baking sheet. Bake until golden, 17 to 20 minutes, then transfer with a metal spatula to racks to cool completely. Make more cookies with remaining dough and filling on a lined cooled baking sheet.