Heat oven to 425°F. Line cookie sheet with cooking parchment paper. In 12-inch skillet, melt 1 tablespoon butter. Cook pears in butter 3 minutes or until just tender. Remove from heat; set aside. In food processor, place 1/4 cup almonds and 1 tablespoon sugar. Cover; process until finely ground. In medium bowl, mix softened butter and remaining 2 tablespoons sugar with spoon until blended. Add egg yolk; stir until well blended. Add flour and ground almond mixture; stir until blended.
Onto cookie sheet, roll pastry sheet into 11-inch square. Cut 1/2-inch-wide strip of pastry from each side of square. Brush edges of dough square with water; place dough strips along each edge to create a border. Spread almond mixture over center of pastry; top with pears. Bake 25 to 28 minutes or until puffed and golden. Brush with jelly; sprinkle with toasted almonds. Serve warm.