Unfold piecrusts on a lightly floured surface, and roll to press out fold lines. Cut with a 2-inch heart-shaped cookie cutter. Reroll remaining dough, and repeat procedure. (There should be a total of 46 pastry hearts.) Brush 1 side of each pastry heart with egg white, and sprinkle evenly with granulated sugar. Place pastry hearts on 2 ungreased baking sheets.
Bake at 400° for 7 to 8 minutes or until lightly browned. Remove hearts to wire racks, and let cool.
Stir together cream cheese, powdered sugar, 2 tablespoons butter, and almond extract until blended.
Spread cream cheese mixture evenly on unsugared sides of half the hearts; spread about 1/2 teaspoon preserves over mixture. Top with remaining hearts, unsugared sides down.
Microwave white chocolate morsels and 1 tablespoon butter in a glass bowl at HIGH 1 minute or until melted. Stir until smooth. Place mixture in a small heavy-duty zip-top bag; seal bag. Snip a tiny hole in 1 corner of bag, and drizzle over tarts. Let cool completely; sprinkle with red sparkling sugar, if desired. Place in candy boxes, if desired.