1-Cut the Puff Pastry: Cut the Puff Pastry: Line a large baking sheet with parchment paper. Unroll the cold puff pastry. Use a leaf-shaped cookie cutter to cut out 12 evenly sized leaves. Arrange the leaves close together on the prepared baking sheet without overlapping.
2-Chill the Pastry: Chill the Pastry: Refrigerate the cut pastry leaves for 10-15 minutes while the oven preheats. Keeping the pastry cold helps maintain its crisp, flaky layers.
3-Preheat the Oven: Preheat the Oven: Preheat the oven to 400°F (205°C). Use a fork to prick holes all over each pastry leaf. This allows steam to escape and prevents the pastry from rising too high.
4-Bake the Leaves Flat: Bake the Leaves Flat: Place a second sheet of parchment paper over the pastry leaves. Set another full-size baking sheet directly on top. Place a small oven-safe baking dish on the top pan to keep it securely pressed down. The puff pastry should be sandwiched between the two baking sheets. Bake for 15 minutes. Carefully remove the top baking sheet and upper sheet of parchment paper. Continue baking uncovered for another 5-7 minutes, or until the leaves are evenly golden brown and crisp. Transfer the pastry leaves to a wire rack and let them cool completely.
5-Prepare the Pumpkin Cream: Prepare the Pumpkin Cream: Add the chilled heavy cream, pumpkin purée, powdered sugar, vanilla bean paste, and pumpkin pie spice to a cold mixing bowl. Whip with an electric mixer for 3-4 minutes, beginning on medium speed and gradually increasing to high. Stop mixing as soon as the cream holds firm peaks. Do not overwhip. Transfer the pumpkin cream to a piping bag fitted with a round or star piping tip.
6-Assemble the Pastries: Assemble the Pastries: Place one pastry leaf on a serving plate. Pipe a layer of pumpkin cream over the leaf. Add a second pastry leaf and pipe another layer of cream on top. Finish with a third pastry leaf. Repeat with the remaining pastry and filling to make 4 tiered desserts. Dust lightly with powdered sugar and serve immediately.