Thaw puff pastry according to package directions.
Stir together sugar and cornstarch in medium-size saucepan until blended. Stir in cranberries, pears, ginger, lime juice and allspice. Bring to simmering over medium heat, stirring occasionally; simmer 8 minutes or until the fruits are tender. Set aside to cool.
Preheat oven to 350°F.
Cut one sheet of pastry in half across the width. Roll out each half with a lightly floured rolling pin on a lightly floured surface, one piece into a 15 x 7-inch rectangle and the other into a 14 x 6-inch rectangle. Fold larger rectangle lengthwise in half. Along long folded edge, cut parallel slits, 1/2 inch apart and about 2-1/2 inches long.
Place the smaller rectangle on an ungreased baking sheet. Spread half of the filling lengthwise down the center in a 3-inch-wide strip, leaving a 1-1/2-inch border at each short end of the pastry
Brush edges of pastry around filling with egg. Top with remaining larger pastry sheet, pressing edges lightly to seal. Brush top lightly with egg. Trim edges even with a sharp knife. Repeat with remaining sheet of pastry and filling.
Bake in preheated 350°F oven for 45 minutes or until golden brown. Cool to room temperature. Serve with sweetened whipped cream if you wish.