TO MAKE FILLING
Heat apples, apricots, sugar, and water to boiling in small sauce pan.
Reduce heat and simmer, uncovered, until fruit is tender and water is absorbed, about 10 minutes.
Process mixture in food processor or blender until smooth. Allow to cool.
TO MAKE DOUGH
Beat butter and sugar in medium bowl until fluffy. Beat in egg, egg whites, and vanilla.
Mix in combined flour, baking soda, and salt.
Divide dough into 4 equal parts; roll each into a log about 5 inches long. Refrigerate, covered, until firm, about 2 hours.
Roll 1 piece dough on floured surface into rectangle 12 x 4 inches. Spread 1¼ of the fruit filling in a 1½ inch strip in center of dough.
Fold sides of dough over filling, pressing edges to seal. Cut filled dough in half and place on greased cookie sheet. Repeat with remaining dough and filling. Brush top of dough lightly with milk.
Bake in preheated 400 F oven until lightly browned, 10 to 12 minutes. Remove from pan and cool on wire racks
Cut into 1-½ inch bars. Store in airtight container.
Makes about 30 bars.