Beat butter and cream cheese with an electric mixer on low speed in a bowl until blended and smooth.

Beat in vanilla extract, salt, 1 cup flour, and ¼ cup sugar until blended.

Stir in remaining flour by hand using a spoon.

Divide dough into 4 equal pieces. Wrap each piece with plastic wrap and refrigerate until firm, at least 2 hours or overnight.

Stir walnuts, apricots, brown sugar, ¼ cup plus 2 tablespoons white sugar, and ½ teaspoon cinnamon in a medium bowl until well-mixed. Set filling aside.

Preheat the oven to 325 degrees F (165 degrees C). Line 2 large baking sheets with foil and grease foil.

Roll one piece of chilled dough on a lightly floured surface with a floured rolling pin into a 9-inch round.

Spread 2 tablespoons raspberry preserves on top. Sprinkle with about ½ cup apricot filling; gently press filling onto dough.

Cut dough into 12 equal wedges with a sharp knife or pastry wheel. Starting at curved edge, roll up each wedge, jelly-roll fashion.

Place cookies on the prepared sheets, point-side down, about ½ inch apart. Repeat with remaining dough.

Mix remaining 2 tablespoons sugar with 1 teaspoon cinnamon in a small bowl.

Use a pastry brush to brush rugelach with milk. Sprinkle with cinnamon sugar.

Bake rugelach in the preheated oven on 2 racks until golden, 30 to 35 minutes; rotate cookie sheets between upper and lower racks halfway through baking time.

Immediately remove rugelach to wire racks to cool. Store cooled rugelach in a tightly covered container.