Heat oven to 400°F. Unfold puff pastry sheets. Using a sharp knife, cut each pastry sheet into quarters, making 4 equal rectangles. Divide each rectangle in half diagonally. Transfer triangles, 8 per pastry sheet, for a total of 16, to ungreased baking sheets.
Bake in 400°F oven 12 to 14 minutes or until puffed and golden brown. Remove triangles to wire racks to cool completely. Prop triangles up on long straight side; with serrated knife, split each triangle into 3 triangles, for a total of 48 triangles.
Transfer frosting to microwave-safe measuring cup. Either microwave on 100% power for 40 to 50 seconds, or melt over almost simmering water in a saucepan. Stir in the Kirsch, if using. Transfer melted frosting to pastry bag, fitted with small round tip.
Beginning with 16 pastry triangle bottoms, spoon 2 tablespoons cherry pie filling onto each. Drizzle with melted frosting; top each with 2 tablespoons whipped topping. Top each with middle layer of pastry; repeat layering cherry filling, frosting and whipped topping. Top with reserved pastry tops. Drizzle with any remaining chocolate frosting.