On a lightly floured surface, roll pastry sheet into a 14x10-in. rectangle. Using three different sizes of heart-shaped cookie cutters (3-1/2 in., 3 in. and 1 in.), cut out 12 hearts, four of each size (discard scraps).
Place 2 in. apart on a greased baking sheet. Sprinkle with cinnamon-sugar. Bake at 400° for 8-10 minutes or until golden brown; remove smallest hearts to a wire rack. Bake medium and large hearts 2 minutes longer; remove to a wire rack.
In a small microwave-safe bowl, melt chocolate chips and shortening; stir until smooth. Transfer mixture to a small resealable plastic bag; cut a small hole in a corner of bag. In a small bowl, beat cream until it begins to thicken. Add sugar and vanilla; beat until stiff peaks form.
To assemble, place large pastry hearts on dessert plates; top with a third of the whipped cream and half of the strawberries. Drizzle with chocolate. Top with medium hearts, another third of the whipped cream and remaining strawberries. Drizzle with chocolate. Dollop with remaining whipped cream. Pipe chocolate around edge of small hearts; insert into whipped cream at top of tower.