Creating perfect Raspberry Cream Napoleons is a straightforward process. Follow these steps to achieve a brilliant dessert:

1. Preheat Oven: Preheat your oven to 400°F (200°C).
2. Prepare Pastry: Roll out the thawed puff pastry on a floured surface to about 1/8 inch thick. Cut out rectangular pieces, approximately 3 inches by 4 inches.
3. Bake Pastry: Place the rectangles on a parchment-lined baking sheet. Prick each piece with a fork to prevent them from puffing up too much. Bake for 15-20 minutes or until golden brown and crispy.
4. Cool Pastry: After baking, remove the pastry from the oven and allow them to cool completely on a wire rack.
5. Make Cream Filling: In a mixing bowl, whip the heavy cream until it starts to thicken. Gradually add the powdered sugar and vanilla extract, continuing to whip until stiff peaks form.
6. Incorporate Raspberries: Gently fold in the fresh raspberries and raspberry jam into the whipped cream mixture. This will give the cream a lovely raspberry flavor while retaining some berry texture.
7. Assemble Napoleons: Once the pastry layers have cooled, take one piece and spread a generous amount of the raspberry cream filling on top. Place another piece of pastry on top and repeat the process until you have built a tower of three layers.
8. Dust with Powdered Sugar: Finish off by dusting the top layer with powdered sugar. If desired, add a few whole raspberries on top for decoration.
9. Chill and Serve: Refrigerate the assembled Napoleons for at least 30 minutes before serving. This will help the layers set and enhance flavors.