Make the quick puff pastry and let it cool in the frezeer at least 30 minutes.
Make the pastry cream and pour into a shallow large bowl so it cools fast. First, let it cool at room temperature and then keep it the fridge.
Preheat the oven to 390°F(200°C).
Remove the puff pastry from the freezer. Lightly flour the work surface, the rolling pin, and the top of the dough. Roll out the dough almost ⅛ inch (3mm) thick, 10,5*10 inch (27*25cm) long.
Place the dough on the baking sheet covered with parchment paper. Prick the dough with a fork. Put a parchment paper over the dough and put another baking sheet on top to hold the pastry down. (If the dough gets warm, put it in the fridge to let it cool before you bake.)
Bake for almost 15-19 minutes with the baking sheet on top or until it is lightly brown. Remove the top baking sheet and bake for almost extra 3-4 more minutes or until it is golden brown. Baking time may change from oven to oven so check the oven after 10 minutes.
Remove the pastry from the oven. Trim the pastry from the edges to make it neat. Keeping the long side in front of you, cut it into 3 equal pieces and keep them aside.
Whip the heavy cream with powdered sugar until soft peaks form. Whisk pastry cream to avoid any lumps. Keep it aside. Gently fold whipped cream into the pastry cream in 3 batches.
Using a spatula or a piping bag, apply at least ⅓ of the pastry cream onto the first layer, then put the second layer on top and apply at least ⅓ of the pastry cream or as much as you want on top. Put the third layer on top of the second layer and sift powdered sugar on top. Cut into 4 equal pieces to serve.