Preheat oven to 350 degrees. Combine lemon juice with 4 cups water in large bowl. Peel pears; place in lemon-water and set aside.Sprinkle work surface with flour. Roll each sheet puff pastry to 12-inch x 8-inch rectangle. Cut each sheet in half lengthwise. Transfer to parchment paper-lined baking sheet and chill 20 min.
Make poaching liquid: Combine sugar with remaining 4 cups water in medium saucepan; stir to dissolve. Add wine, cinnamon sticks, and vanilla; heat to boiling on MEDIUM. Reduce heat to MEDIUM-LOW; simmer 10 min to infuse flavors.
Remove pears from lemon-water; cut in half and scoop out core using metal spoon or melon baller. Lower pear halves gently into poaching liquid. Top with small plate to keep submerged, and poach on MEDIUM-LOW, until consistency of firm canned pears, about 12-15 min. Remove from liquid; cool (or leave in liquid for later use). While pears cool, combine almond paste, egg white, and kirschwasser in small bowl; set aside. Combine sugar and cinnamon in small bowl. Set aside.
Lightly grease 2 nonstick baking sheets (may use parchment paper). Place 2 puff pastry sheets on 1 baking sheet and 1 on the other. Brush cutting surface with water; cut leftover sheet of pastry lengthwise in 6 even strips. Brush each sheet with beaten egg (this will act as "glue"). To create edges to keep filling in, place 1 thin strip lengthwise down each long side of the tarts. Pierce bottom of tart shells with a fork.
Divide almond filling into thirds; spread evenly on each of the 3 tarts. Slice pear halves thinly, trying to keep half-pear shape. (Use 4 pear halves per tart.) Arrange slices widthwise across tart in alternating directions. Sprinkle with cinnamon-sugar mix. Place in oven on center rack and bake until bottom is golden brown, about 20 min.
Prepare clear glaze as directed on package. Remove tarts from oven; immediately brush with glaze and sprinkle with toasted walnuts.
Chef tip: A good quality canned pear can be used in place of poached pears. Poached pears can be stored in refrigerator for 2-3 days.
Values per serving: