Combine flour and salt in a food processor bowl. Cover and process until mixed. Add butter and cream cheese; process until well combined. (Or, beat together softened butter and cream cheese in a medium mixing bowl with an electric mixer until combined. Add the flour and salt; beat on low speed just until combined.) Divide dough in half. Wrap in plastic wrap and chill 1 hour or until easy to handle.
Roll each portion of dough on a lightly floured surface until 1/8 inch thick. Cut out cookies with a floured 2-inch heart-shape cutter. Place half of the cutouts on an ungreased cookie sheet. Place a scant 1/4 teaspoon each of preserves and almond paste in the center of each heart. Combine beaten egg and water. Brush cookie edges with egg mixture. Top each cookie with a plain heart cutout. Lightly press edges together; seal with a fork around all of the edges.
Brush finished cookies with egg mixture; if desired, sprinkle tops lightly with coarse sugar. Bake in a 375 degree F oven for 10 to 12 minutes or until golden. Transfer to wire racks and cool. Makes about 52 hearts.